]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1337hwp:master-id:clincanres;1078-0432.CCR-17-1337American Association for Cancer Research2017-12-01CCR Drug Updates232371657170http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7171?rss=1
Purpose: We aimed to evaluate the performance of therapeutic drug monitoring (TDM) approach in controlling interpatient variability of carboplatin exposure (AUC) in patients treated with TI-CE high-dose chemotherapy for advanced germ cell tumors and to assess the possibility of using a formula-based dosing method as a possible alternative.

Experimental Design: Eighty-nine patients receiving carboplatin for 3 consecutive days during 3 cycles were evaluable for pharmacokinetic study. Blood samples were taken on day 1 to determine the carboplatin clearance using a Bayesian approach (NONMEM 7.2) and to adjust the dose on day 3 to reach the target AUC of 24 mg.min/mL over 3 days. On days 2 and 3, samples were taken for retrospective assessment of the actual AUC. A population pharmacokinetic analysis was also performed on 58 patients using NONMEM to develop a covariate equation for carboplatin clearance prediction adapted for future TI-CE patients, and its performance was prospectively evaluated on the other 29 patients along with different methods of carboplatin clearance prediction.

Results: The mean actual AUC was 24.4 mg.min/mL per cycle (22.4 and 26.8 for 10th and 90th percentiles, respectively). The new covariate equation [CL (mL/min) = 130.7 x (Scr/83)–0.826x (BW/76)+0.907x (Age/36)–0.223 with Scr in μmol/L, BW in kilograms, age in years] allows unbiased and more accurate prediction of carboplatin clearance compared with other equations.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1344hwp:master-id:clincanres;1078-0432.CCR-17-1344American Association for Cancer Research2017-12-01Cancer Therapy: Clinical232371717179http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7180?rss=1
Purpose: Radotinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor (TKI) approved in Korea for chronic phase chronic myeloid leukemia (CML-CP) in patients newly diagnosed or with insufficient response to other TKIs. This study was conducted to evaluate the efficacy and safety of radotinib as first-line therapy for CML-CP.

Experimental Design: This multinational, open-label study assigned patients (1:1:1) to one of two twice-daily radotinib doses, or imatinib daily. The primary endpoint was major molecular response (MMR) by 12 months.

Results: With a median follow-up of 60 months, 65.4% of patients achieved an optimal response (OR), 5.6% were classified as "warnings," 22.4% failed imatinib, and 6.6% switched to a different TKI because of drug intolerance. We recorded 19 deaths (6.9%), seven (2.5%) attributable to disease progression. We found that higher BCR–ABL/GUSIS levels at diagnosis were associated with inferior rates of OR (P < 0.001), FFS (P < 0.001), and EFS (P < 0.001). Elevated BCR–ABL/GUSIS levels were also associated with lower rates of TFS (P = 0.029) but not with OS (P = 0.132). Similarly, high BCR–ABL/ABL levels at diagnosis were associated with inferior rates of OR (P = 0.03), FFS (P = 0.001), and EFS (P = 0.005), but not with TFS (P = 0.167) or OS (P = 0.052). However, in internal validation experiments, GUS outperformed ABL in samples collected at diagnosis as the latter produced 80% misclassification rates.

Experimental Design: Clear cell histology, no prior treatments, and being sufficiently fit to receive high-dose IL2 were the main eligibility criteria. The phase I portion consisted of two dose levels of entinostat (3 and 5 mg, orally every 14 days) and a fixed standard dose of IL2 (600,000 U/kg i.v.). Each cycle was 85 days. The primary endpoint was objective response rate and toxicity. Secondary endpoints included progression-free survival and overall survival.

Results: Forty-seven patients were enrolled. At a median follow-up of 21.9 months, the objective response rate was 37% [95% confidence interval (CI), 22%–53%], the median progression-free survival was 13.8 months (95% CI, 6.0–18.8), and the median overall survival was 65.3 months (95% CI, 52.6.-65.3). The most common grade 3/4 toxicities were hypophosphatemia (16%), lymphopenia (15%), and hypocalcemia (7%), and all were transient. Decreased Tregs were observed following treatment with entinostat, and lower numbers were associated with response (P = 0.03).

Experimental Design: Somatic variations in 46 pairs of matched primary-liver metastatic tumors and 42 primary tumors without metastasis were analyzed by whole-exome sequencing. Tumor clonality was estimated from single-nucleotide and copy-number variations. The correlation between clinical parameters of patients and clonal heterogeneity in liver metastasis was evaluated.

Results: Tumor heterogeneity across colorectal cancer samples was highly variable; however, a high degree of tumor heterogeneity was associated with a worse disease-free survival. Highly heterogeneous primary colorectal cancer was correlated with a higher rate of liver metastasis. Recurrent somatic mutations in APC, TP53, and KRAS were frequently detected in highly heterogeneous colorectal cancer. The variant allele frequency of these mutations was high, while somatic mutations in other genes such as PIK3CA and NOTCH1 were low. The number and distribution of primary colorectal cancer subclones were preserved in metastatic tumors.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-0306hwp:master-id:clincanres;1078-0432.CCR-17-0306American Association for Cancer Research2017-12-01Personalized Medicine and Imaging232372097216http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7217?rss=1
Purpose: The study objective was to characterize the prognostic performance of a novel Breast Cancer Index model (BCIN+), an integration of BCI gene expression, tumor size, and grade, specifically developed for assessment of distant recurrence (DR) risk in HR+ breast cancer patients with one to three positive lymph nodes (pN1).

Experimental Design: Analysis was conducted in a well-annotated retrospective series of pN1 patients (N = 402) treated with adjuvant endocrine therapy with or without chemotherapy using a prespecified model. The primary endpoint was time-to-DR. Results were determined blinded to clinical outcome. Kaplan-Meier estimates of overall (0–15 years) and late (≥5 years) DR, HRs, and 95% confidence interval (CIs) were estimated. Likelihood ratio statistics assessed relative contributions of prognostic information.

Results: The majority of metastases were classified into intermediate or high-risk groups by all signatures, and a significant association was found between metastatic signature subgroups and primary tumor estrogen receptor status and histologic grade (P < 0.05). When considering all sites of metastasis, only PAM50 was statistically significant in Kaplan–Meier analysis (Log-rank P = 0.008 and 0.008 for long- and short-term postrelapse breast cancer–specific survival, respectively). This significance remained in both uni- and multivariate models when restricting analyses to lymph node metastases only, and a similar trend was observed in other metastatic sites combined, but did not reach formal significance.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-2301hwp:master-id:clincanres;1078-0432.CCR-17-2301American Association for Cancer Research2017-12-01Personalized Medicine and Imaging232372257231http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7232?rss=1
Purpose: Molecular classification of endometrial cancer identified distinct molecular subgroups. However, the largest subset of endometrial cancers remains poorly characterized and is referred to as the "nonspecific molecular profile" (NSMP) subgroup. Here, we aimed at refining the classification of this subgroup by profiling somatic copy-number aberrations (SCNAs).

Experimental Design: Anti-CD20 cys-diabody (cDb) and cys-minibody (cMb) based on rituximab and obinutuzumab (GA101) were radioiodinated and used for immunoPET imaging of a murine lymphoma model. Pairwise comparison of obinutuzumab-based antibody fragments labeled with residualizing (89Zr) versus non-residualizing (124I) radionuclides by region of interest analysis of serial PET images was conducted both in the murine lymphoma model and in huCD20TM to assess antigen modulation in vivo.

Results:124I-GAcDb and 124I-GAcMb produced high-contrast immunoPET images of B-cell lymphoma and outperformed the respective rituximab-based tracers. ImmunoPET imaging of huCD20TM showed specific uptake in lymphoid tissues. The use of the radiometal 89Zr as alternative label for GAcDb and GAcMb yielded greater target-specific uptake and retention compared with 124I-labeled tracers. Pairwise comparison of 89Zr- and 124I-labeled GAcDb and GAcMb allowed assessment of in vivo internalization of CD20/antibody complexes and revealed that CD20 internalization differs between malignant and endogenous B cells.

Experimental Design: We enrolled 222 patients (152 in the primary cohort and 70 in the validation cohort) with clinicopathologically confirmed LARC who received chemoradiotherapy before surgery. All patients underwent T2-weighted and diffusion-weighted imaging before and after chemoradiotherapy; 2,252 radiomic features were extracted from each patient before and after treatment imaging. The two-sample t test and the least absolute shrinkage and selection operator regression were used for feature selection, whereupon a radiomics signature was built with support vector machines. Multivariable logistic regression analysis was then used to develop a radiomics model incorporating the radiomics signature and independent clinicopathologic risk factors. The performance of the radiomics model was assessed by its calibration, discrimination, and clinical usefulness with independent validation.

Results: The radiomics signature comprised 30 selected features and showed good discrimination performance in both the primary and validation cohorts. The individualized radiomics model, which incorporated the radiomics signature and tumor length, also showed good discrimination, with an area under the receiver operating characteristic curve of 0.9756 (95% confidence interval, 0.9185–0.9711) in the validation cohort, and good calibration. Decision curve analysis confirmed the clinical utility of the radiomics model.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1038hwp:master-id:clincanres;1078-0432.CCR-17-1038American Association for Cancer Research2017-12-01Personalized Medicine and Imaging232372537262http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7263?rss=1
Purpose: Survival for pancreatic ductal adenocarcinoma (PDAC) patients is extremely poor and improved therapies are urgently needed. Tumor-infiltrating lymphocyte (TIL) adoptive cell therapy (ACT) has shown great promise in other tumor types, such as metastatic melanoma where overall response rates of 50% have been seen. Given this success and the evidence showing that T-cell presence positively correlates with overall survival in PDAC, we sought to enrich for CD8+ TILs capable of autologous tumor recognition. In addition, we explored the phenotype and T-cell receptor repertoire of the CD8+ TILs in the tumor microenvironment.

Experimental Design: We used an agonistic 4-1BB mAb during the initial tumor fragment culture to provide 4-1BB costimulation and assessed changes in TIL growth, phenotype, repertoire, and antitumor function.

Results: Increased CD8+ TIL growth from PDAC tumors was achieved with the aid of an agonistic 4-1BB mAb. Expanded TILs were characterized by an activated but not terminally differentiated phenotype. Moreover, 4-1BB stimulation expanded a more clonal and distinct CD8+ TIL repertoire than IL2 alone. TILs from both culture conditions displayed MHC class I-restricted recognition of autologous tumor targets.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-0831hwp:master-id:clincanres;1078-0432.CCR-17-0831American Association for Cancer Research2017-12-01Cancer Therapy: Preclinical232372637275http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7276?rss=1
Purpose: DNA methylation in human papillomavirus–associated (HPV+) head and neck squamous cell carcinoma (HNSCC) may have importance for continuous expression of HPV oncogenes, tumor cell proliferation, and survival. Here, we determined activity of a global DNA-demethylating agent, 5-azacytidine (5-aza), against HPV+ HNSCC in preclinical models and explored it as a targeted therapy in a window trial enrolling patients with HPV+ HNSCC.

Experimental Design: Sensitivity of HNSCC cells to 5-aza treatment was determined, and then 5-aza activity was tested in vivo using xenografted tumors in a mouse model. Finally, tumor samples from patients enrolled in a window clinical trial were analyzed to identify activity of 5-aza therapy in patients with HPV+ HNSCC.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1438hwp:master-id:clincanres;1078-0432.CCR-17-1438American Association for Cancer Research2017-12-01Cancer Therapy: Preclinical232372767287http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7288?rss=1
Purpose: Preoperative aromatase inhibitor (AI) therapy has demonstrated efficacy in hormone receptor (HR)-positive postmenopausal breast cancer. However, many patients have disease that is either intrinsically resistant to AIs or that responds initially but develops resistance after prolonged exposure. We have shown that patients with breast tumors expressing the deregulated forms of cyclin E [low molecular weight forms (LMW-E)] have poor overall survival. Herein, we hypothesize that LMW-E expression can identify HR-positive tumors that are unresponsive to neoadjuvant AI therapy due to the inability of AIs to induce a cytostatic effect.

Experimental Design: LMW-E was examined in breast cancer specimens from 58 patients enrolled in the American College of Surgeons Oncology Group Z1031, a neoadjuvant AI clinical trial. The mechanisms of LMW-E–mediated resistance to AI were evaluated in vitro and in vivo using an inducible model system of cyclin E (full-length and LMW-E) in aromatase-overexpressing MCF7 cells.

Results: Breast cancer recurrence-free interval was significantly worse in patients with LMW-E–positive tumors who received AI neoadjuvant therapy, compared with those with LMW-E negative tumors. Upon LMW-E induction, MCF7 xenografts were unresponsive to letrozole in vivo, resulting in increased tumor volume after treatment with AIs. LMW-E expression overcame cell-cycle inhibition by AIs in a CDK2/Rb-dependent manner, and inhibition of CDK2 by dinaciclib reversed LMW-E–mediated resistance, whereas treatment with palbociclib, a CDK4/6 inhibitor, did not.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1544hwp:master-id:clincanres;1078-0432.CCR-17-1544American Association for Cancer Research2017-12-01Cancer Therapy: Preclinical232372887300http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7301?rss=1
Purpose: Although many cancers are showing remarkable responses to targeted therapies, pediatric sarcomas, including Ewing sarcoma, remain recalcitrant. To broaden the therapeutic landscape, we explored the in vitro response of Ewing sarcoma cell lines against a large collection of investigational and approved drugs to identify candidate combinations.

Experimental Design: Drugs displaying activity as single agents were evaluated in combinatorial (matrix) format to identify highly active, synergistic drug combinations, and combinations were subsequently validated in multiple cell lines using various agents from each class. Comprehensive metabolomic and proteomic profiling was performed to better understand the mechanism underlying the synergy. Xenograft experiments were performed to determine efficacy and in vivo mechanism.

Results: Several promising candidates emerged, including the combination of small-molecule PARP and nicotinamide phosphoribosyltransferase (NAMPT) inhibitors, a rational combination as NAMPTis block the rate-limiting enzyme in the production of nicotinamide adenine dinucleotide (NAD+), a necessary substrate of PARP. Mechanistic drivers of the synergistic cell killing phenotype of these combined drugs included depletion of NMN and NAD+, diminished PAR activity, increased DNA damage, and apoptosis. Combination PARPis and NAMPTis in vivo resulted in tumor regression, delayed disease progression, and increased survival.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1121hwp:master-id:clincanres;1078-0432.CCR-17-1121American Association for Cancer Research2017-12-01Cancer Therapy: Preclinical232373017311http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7312?rss=1
Purpose: Mutation of the Kirsten ras sarcoma viral oncogene homolog (KRAS) and loss of p53 function are commonly seen in patients with non–small cell lung cancer (NSCLC). Combining therapeutics targeting these tumor-defensive pathways with cisplatin in a single-nanoparticle platform are rarely developed in clinic.

Experimental Design: Cisplatin was encapsulated in liposomes, which multiple polyelectrolyte layers, including siKRAS and miR-34a were built on to generate multifunctional layer-by-layer nanoparticle. Structure, size, and surface charge were characterized, in addition to in vitro toxicity studies. In vivo tumor targeting and therapy was investigated in an orthotopic lung cancer model by microCT, fluorescence imaging, and immunohistochemistry.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-16-2186hwp:master-id:clincanres;1078-0432.CCR-16-2186American Association for Cancer Research2017-12-01Cancer Therapy: Preclinical232373127323http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7324?rss=1
Purpose: TMEM16A is a calcium-activated chloride channel that is amplified in a variety of cancers, including 30% of head and neck squamous cell carcinomas (HNSCCs), raising the possibility of an anti-apoptotic role in malignant cells. This study investigated this using a multimodal, translational investigation.

Results: TMEM16A expression was found to correlate with greater tumor size, increased Erk 1/2 activity, less Bim expression, and less apoptotic activity overall in human HNSCC. These findings were corroborated in subsequent in vitro and in vivo studies and expanded to include a cisplatin-resistant phenotype with TMEM16A overexpression. A cohort of 41 patients with laryngeal cancer demonstrated that cases that recurred after chemoradiation failure were associated with a greater TMEM16A overexpression rate than HNSCC that did not recur.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1561hwp:master-id:clincanres;1078-0432.CCR-17-1561American Association for Cancer Research2017-12-01Cancer Therapy: Preclinical232373247332http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7333?rss=1
Purpose: Hepatocellular carcinoma (HCC) often arises in the setting of chronic liver inflammation and may be responsive to novel immunotherapies.

Experimental Design: To characterize the immune microenvironment in HCC, IHC staining was performed for CD8-positive T lymphocytes, PD-1–positive, and LAG-3–positive lymphocytes, CD163-positive macrophages, and PD-L1 expression in tumor and liver background from 29 cases of resected HCC.

Results: Expression of CD8 was reduced in tumor, and expression of CD163 was reduced at the tumor interface. Positive clusters of PD-L1 expression were identified in 24 of 29 cases (83%), and positive expression of LAG-3 on tumor-infiltrating lymphocytes was identified in 19 of 29 cases (65%). The expression of both PD-L1 and LAG-3 was increased in tumor relative to liver background. No association between viral status or other clinicopathologic features and expression of any of the IHC markers investigated was noted.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-0950hwp:master-id:clincanres;1078-0432.CCR-17-0950American Association for Cancer Research2017-12-01Cancer Therapy: Preclinical232373337339http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7340?rss=1
Purpose: Dysregulated expression of PLD1 has emerged as a hallmark feature of colorectal cancer, which remains a major cause of mortality worldwide. Aberrant activation of Wnt/β-catenin signaling is a critical event in the development of colorectal cancer. Here, we investigated molecular crosstalk between the Wnt/β-catenin and PI3K/Akt pathways via inhibitor of β-catenin and T-cell factor (ICAT), a negative regulator of Wnt/β-catenin signaling. We also explored the effect of PLD1 inhibition on growth of colorectal cancer hyperactivated by Wnt/β-catenin and PI3K/Akt signaling.

Experimental Design: Expression of ICAT via targeting of PLD1 was assessed in vivo in ApcMin/+ mice, an AOM/DSS model, and in vitro using various colorectal cancer cells. The relationship between ICAT/PLD1 expression and prognostic survival value of 153 colorectal cancer patients was examined. The therapeutic efficacy of PLD1 inhibitor was determined using a patient-derived xenograft model carrying APC and PI3K mutations.

Results: In patients with germline T790M mutations, the T790M allelic fraction (AF) in cfDNA approximates 50%, higher than that of EGFR driver mutations. Review of plasma NGS results reveals three groups of variants: a low-AF tumor group, a heterozygous group (~50% AF), and a homozygous group (~100% AF). As the EGFR driver mutation AF increases, the distribution of the heterozygous group changes, suggesting increased copy number variation from increased tumor content. Excluding cases with high copy number variation, mutations can be differentiated into somatic variants and incidentally identified germline variants. We then developed a bioinformatic algorithm to distinguish germline and somatic mutations; blinded validation in 21 cases confirmed a 100% positive predictive value for predicting germline T790M. Querying a database of 31,414 patients with plasma NGS, we identified 48 with germline T790M, 43 with nonsquamous NSCLC (P < 0.0001).

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1745hwp:master-id:clincanres;1078-0432.CCR-17-1745American Association for Cancer Research2017-12-01Biology of Human Tumors232373517359http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7360?rss=1
Purpose: CD90 (Thy-1) is a glycophosphatidylinositol-anchored glycoprotein considered as a surrogate marker for a variety of stem cells, including glioblastoma (GBM) stem cells (GSC). However, the molecular and cellular functions of CD90 remain unclear.

Experimental Design: The function of CD90 in GBM was addressed using cellular models from immortalized and primary GBM lines, in vivo orthotopic mouse models, and GBM specimens' transcriptome associated with MRI features from GBM patients. CD90 expression was silenced in U251 and GBM primary cells and complemented in CD90-negative U87 cells.

Results: We showed that CD90 is not only expressed on GSCs but also on more differentiated GBM cancer cells. In GBM patients, CD90 expression was associated with an adhesion/migration gene signature and with invasive tumor features. Modulation of CD90 expression in GBM cells dramatically affected their adhesion and migration properties. Moreover, orthotopic xenografts revealed that CD90 expression induced invasive phenotypes in vivo. Indeed, CD90 expression led to enhanced SRC and FAK signaling in our GBM cellular models and GBM patients' specimens. Pharmacologic inhibition of these signaling nodes blunted adhesion and migration in CD90-positive cells. Remarkably, dasatinib blunted CD90-dependent GBM cell invasion in vivo and killed CD90high primary GSC lines.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1549hwp:master-id:clincanres;1078-0432.CCR-17-1549American Association for Cancer Research2017-12-01Biology of Human Tumors232373607374http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7375?rss=1
Purpose: Tumor-associated macrophages (TAMs) are frequently associated with poor prognosis in human cancers. However, the effects of TAMs in colorectal cancer are contradictory. We therefore investigated the functions, mechanisms, and clinical significance of TAMs in colorectal cancer.

Experimental Design: We measured the macrophage infiltration (CD68), P-gp, and Bcl2 expression in colorectal cancer tissues using IHC staining. Coculture of TAMs and colorectal cancer cells both in vitro and in vivo models was used to evaluate the effects of TAMs on colorectal cancer chemoresistance. Cytokine antibody arrays, ELISA, neutralizing antibody, and luciferase reporter assay were performed to uncover the underlying mechanism.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1283hwp:master-id:clincanres;1078-0432.CCR-17-1283American Association for Cancer Research2017-12-01Biology of Human Tumors232373757387http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7388?rss=1
Purpose: Bladder cancer is a current clinical and social problem. At diagnosis, most patients present with nonmuscle-invasive tumors, characterized by a high recurrence rate, which could progress to muscle-invasive disease and metastasis. Bone morphogenetic protein (BMP)–dependent signaling arising from stromal bladder tissue mediates urothelial homeostasis by promoting urothelial cell differentiation. However, the possible role of BMP ligands in bladder cancer is still unclear.

Experimental Design: Tumor and normal tissue from 68 patients with urothelial cancer were prospectively collected and analyzed for expression of BMP and macrophage markers. The mechanism of action was assessed in vitro by experiments with bladder cancer cell lines and peripheral blood monocyte–derived macrophages.

Results: We observed BMP4 expression is associated and favored type II macrophage differentiation. In vitro experiments showed that both recombinant BMP4 and BMP4-containing conditioned media from bladder cancer cell lines favored monocyte/macrophage polarization toward M2 phenotype macrophages, as shown by the expression and secretion of IL10. Using a series of human bladder cancer patient samples, we also observed increased expression of BMP4 in advanced and undifferentiated tumors in close correlation with epithelial–mesenchymal transition (EMT). However, the p-Smad 1,5,8 staining in tumors showing EMT signs was reduced, due to the increased miR-21 expression leading to reduced BMPR2 expression.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-1004hwp:master-id:clincanres;1078-0432.CCR-17-1004American Association for Cancer Research2017-12-01Biology of Human Tumors232373887399http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7400?rss=1
Purpose: The relative importance of fallopian tube (FT) compared with ovarian surface epithelium (OSE) in the genesis of serous type of ovarian cancer (SOC) is still unsettled. Here, we followed an integrated approach to study the tissue origin of SOC, as well as its association with clinical outcome and response to therapeutic drugs.

Experimental Design: A collection of transcriptome data of 80 FTs, 89 OSEs, and 2,668 SOCs was systematically analyzed to determine the characteristic of FT-like and OSE-like tumors. A molecular signature was developed for identifying tissue origin of SOC and then was used to reevaluate the prognostic genes and therapeutic biomarkers of SOC of different tissue origins. IHC staining of tissue array and functional experiments on a panel of ovarian cancer cell lines were used to further validate the key findings.

Results: The expression patterns of tissue-specific genes, prognostic genes, and molecular markers all support a dualistic tissue origin of SOC, from either FT or OSE. A molecular signature was established to identify the tissue identity of SOCs. Surprisingly, the signature showed a strong association with overall survival (OSE-like vs. FT-like, HR = 4.16; 95% CI, 2.67–6.48; P < 10–9). The pharmacogenomic approach revealed AXL to be a therapeutic target of the aggressive OSE-derived SOC.

]]>2017-11-30T21:05:54-08:00info:doi/10.1158/1078-0432.CCR-17-0527hwp:resource-id:clincanres;23/23/7412American Association for Cancer Research2017-12-01Biology of Human Tumors232374127425http://clincancerres.aacrjournals.org/cgi/content/short/23/23/7426?rss=1
Purpose: Sclerosing epithelioid fibrosarcoma (SEF) is a highly aggressive soft tissue sarcoma closely related to low-grade fibromyxoid sarcoma (LGFMS). Some tumors display morphologic characteristics of both SEF and LGFMS, hence they are known as hybrid SEF/LGFMS. Despite the overlap of gene fusion variants between these two tumor types, SEF is much more aggressive. The current study aimed to further characterize SEF and hybrid SEF/LGFMS genetically to better understand the role of the characteristic fusion genes and possible additional genetic alterations in tumorigenesis.

Experimental Design: We performed whole-exome sequencing, SNP array analysis, RNA sequencing (RNA-seq), global gene expression analyses, and/or IHC on a series of 13 SEFs and 6 hybrid SEF/LGFMS. We also expressed the FUS-CREB3L2 and EWSR1-CREB3L1 fusion genes conditionally in a fibroblast cell line; these cells were subsequently analyzed by RNA-seq, and expression of the CD24 protein was assessed by FACS analysis.

Results: The SNP array analysis detected a large number of structural aberrations in SEF and SEF/LGFMS, many of which were recurrent, notably DMD microdeletions. RNA-seq identified FUS-CREM and PAX5-CREB3L1 as alternative fusion genes in one SEF each. CD24 was strongly upregulated, presumably a direct target of the fusion proteins. This was further confirmed by the gene expression analysis and FACS analysis on Tet-On 3G cells expressing EWSR1-CREB3L1.

Experimental Design: Fifty-five patients with metastatic colorectal cancer were enrolled in a phase I/II trial and randomly assigned to receive 2-week-long courses of low-dose (50 mg twice a day) cyclophosphamide or not. The absolute number, phenotype, and antitumor function of peripheral blood–derived lymphocyte subsets were monitored throughout treatment, as well as during 18-month follow-up.

Experimental Design: We performed targeted next-generation sequencing (17 genes), p53 immunohistochemistry and HPV testing on 36 VC and 82 precursors (sequencing cohort). Subsequently, the prognostic significance of the three subtypes identified in the sequencing cohort was assessed in a series of 236 VC patients (follow-up cohort).

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-1302hwp:master-id:clincanres;1078-0432.CCR-17-1302American Association for Cancer Research2017-11-15Cancer Therapy: Clinical232267816789http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6790?rss=1
Purpose: The potential of the high-affinity CXCR4 antagonist BL-8040 as a monotherapy-mobilizing agent and its derived graft composition and quality were evaluated in a phase I clinical study in healthy volunteers (NCT02073019).

Experimental Design: The first part of the study was a randomized, double-blind, placebo-controlled dose escalation phase. The second part of the study was an open-label phase, in which 8 subjects received a single injection of BL-8040 (1 mg/kg) and approximately 4 hours later underwent a standard leukapheresis procedure. The engraftment potential of the purified mobilized CD34+ cells was further evaluated by transplanting the cells into NSG immunodeficient mice.

Results: BL-8040 was found safe and well tolerated at all doses tested (0.5–1 mg/kg). The main treatment-related adverse events were mild to moderate. Transient injection site and systemic reactions were mitigated by methylprednisolone, paracetamol, and promethazine pretreatment. In the first part of the study, BL-8040 triggered rapid and substantial mobilization of WBCs and CD34+ cells in all tested doses. Four hours postdose, the count rose to a mean of 8, 37, 31, and 35 cells/μL (placebo, 0.5, 0.75, and 1 mg/kg, respectively). FACS analysis revealed substantial mobilization of immature dendritic, T, B, and NK cells. In the second part, the mean CD34+ cells/kg collected were 11.6 x 106 cells/kg. The graft composition was rich in immune cells.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-16-2919hwp:master-id:clincanres;1078-0432.CCR-16-2919American Association for Cancer Research2017-11-15Cancer Therapy: Clinical232267906801http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6802?rss=1
Purpose: The combination of docetaxel chemotherapy and androgen deprivation therapy (ADT) has become a standard treatment for patients with metastatic prostate cancer. The recently accrued phase III CALGB 90203 trial was designed to investigate the clinical effectiveness of this treatment approach earlier in the disease. Specimens from this trial offer a unique opportunity to interrogate the acute molecular response to docetaxel and ADT and identify potential biomarkers.

Results: Three of 52 patients had only microfocal residual cancer at prostatectomy. The most common alterations included TMPRSS2-ERG fusion (n = 32), TP53 mutation or deletion (n = 11), PTEN deletion (n = 6), FOXA1 (n = 6), and SPOP (n = 4) mutation, with no significant enrichment in posttreated specimens. We did not observe AR amplification or mutations. The degree of AR signaling suppression varied among treated tumors and there was upregulation of both AR and AR-V7 expression as well as a subset of neuroendocrine and plasticity genes.

Experimental Design: Potential eligible patients with clinical stage II/III ER+/HER2– breast cancer were preregistered and received anastrozole (goserelin if premenopausal) for 28 days in cycle 0 pending tumor PIK3CA sequencing. Patients positive for PIK3CA mutation in the tumor were eligible to start MK-2206 (150 mg orally weekly, with prophylactic prednisone) on cycle 1 day 2 (C1D2) and to receive a maximum of four 28-day cycles of combination therapy before surgery. Serial biopsies were collected at preregistration, C1D1 and C1D17.

Results: Fifty-one patients preregistered and 16 of 22 with PIK3CA-mutant tumors received study drug. Three patients went off study due to C1D17 Ki67 >10% (n = 2) and toxicity (n = 1). Thirteen patients completed neoadjuvant therapy followed by surgery. No pCRs were observed. Rash was common. MK-2206 did not further suppress cell proliferation and did not induce apoptosis on C1D17 biopsies. Although AKT phosphorylation was reduced, PRAS40 phosphorylation at C1D17 after MK-2206 persisted. One patient acquired an ESR1 mutation at surgery.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-1260hwp:master-id:clincanres;1078-0432.CCR-17-1260American Association for Cancer Research2017-11-15Cancer Therapy: Clinical232268236832http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6833?rss=1
Purpose: The transcription factor brachyury has been shown in preclinical studies to be a driver of the epithelial-to-mesenchymal transition (EMT) and resistance to therapy of human tumor cells. This study describes the characterization of a Modified Vaccinia Ankara (MVA) vector–based vaccine expressing the transgenes for brachyury and three human costimulatory molecules (B7.1, ICAM-1, and LFA-3, designated TRICOM) and a phase I study with this vaccine.

Results: MVA-brachyury-TRICOM-infected human DCs activated CD8+ and CD4+ T cells specific against the self-antigen brachyury in vitro. No dose-limiting toxicities were observed due to vaccine in cancer patients at any of the three dose levels. One transient grade 3 adverse event (AE) possibly related to vaccine (diarrhea) resolved without intervention and did not recur with subsequent vaccine. All other AEs related to vaccine were transient and ≤grade 2. Brachyury-specific T-cell responses were observed at all dose levels and in most patients.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-1087hwp:master-id:clincanres;1078-0432.CCR-17-1087American Association for Cancer Research2017-11-15Cancer Therapy: Clinical232268336845http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6846?rss=1
Purpose: Approximately 40% of all glioblastomas have amplified the EGFR gene, and about half of these tumors express the EGFRvIII variant. The prognostic role of EGFRvIII in EGFR-amplified glioblastoma patients and changes in EGFRvIII expression in recurrent versus primary glioblastomas remain controversial, but such data are highly relevant for EGFRvIII-targeted therapies.

Experimental Design:EGFR-amplified glioblastomas from 106 patients were assessed for EGFRvIII positivity. Changes in EGFR amplification and EGFRvIII status from primary to recurrent glioblastomas were evaluated in 40 patients with EGFR-amplified tumors and 33 patients with EGFR–nonamplified tumors. EGFR single-nucleotide variants (SNV) were assessed in 27 patients. Data were correlated with outcome and validated in 150 glioblastoma patients from The Cancer Genome Atlas (TCGA) consortium.

Results: Sixty of 106 EGFR-amplified glioblastomas were EGFRvIII-positive (56.6%). EGFRvIII positivity was not associated with different progression-free or overall survival. EGFRvIII status was unchanged at recurrence in 35 of 40 patients with EGFR-amplified primary tumors (87.5%). Four patients lost and one patient gained EGFRvIII positivity at recurrence. None of 33 EGFR-nonamplified glioblastomas acquired EGFR amplification or EGFRvIII at recurrence. EGFR SNVs were frequent in EGFR-amplified tumors, but were not linked to survival.

Results: In blinded tests, HPV ccfDNA was detected in 19 of 19 (100%) patients with HPV-positive metastatic cervical cancer but not in any of the 45 healthy blood donors. The HPV genotype harbored in the patients' tumors was correctly identified in 87 of 87 (100%) sequential patient serum samples from 9 patients who received TIL immunotherapy. In three patients who experienced objective cancer regression after TIL treatment, a transient HPV ccfDNA peak was detected 2–3 days after TIL infusion. Furthermore, persistent clearance of HPV ccfDNA was only observed in two patients who experienced complete response (CR) after TIL immunotherapy.

Experimental Design: A total of 1,133 primary prostatic adenocarcinomas and 43 prostatic small cell carcinomas (NEPC) were screened by MSH2 immunohistochemistry with confirmation by next-generation sequencing (NGS). Microsatellite instability (MSI) was assessed by PCR and NGS (mSINGS).

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0955hwp:master-id:clincanres;1078-0432.CCR-17-0955American Association for Cancer Research2017-11-15Personalized Medicine and Imaging232268636874http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6875?rss=1
Purpose: Despite advances in multimodal therapy, neuroblastomas with hemizygous deletion in chromosome 11q (20%–30%) undergo consecutive recurrences with poor outcome. We hypothesized that patients with 11q-loss may share a druggable molecular target(s) that can be exploited for a precision medicine strategy to improve treatment outcome.

Experimental Design: SNP arrays were combined with next-generation sequencing (NGS) to precisely define the deleted region in 17 primary 11q-loss neuroblastomas and identify allelic variants in genes relevant for neuroblastoma etiology. We assessed PARP inhibitor olaparib in combination with other chemotherapy medications using both in vitro and in vivo models.

Results: We detected that ATM haploinsufficiency and ATM allelic variants are common genetic hallmarks of 11q-loss neuroblastomas. On the basis of the distinct DNA repair pathways triggered by ATM and PARP, we postulated that 11q-loss may define a subgroup of neuroblastomas with higher sensitivity to PARP inhibitors. Noteworthy, concomitant treatment with olaparib and DNA alkylating agent temozolomide potently inhibited growth of cell lines harboring 11q-loss. This drug synergism was less potent when temozolomide was exchanged for cisplatin or irinotecan. Intact 11q cells concomitantly treated with ATM inhibitor displayed growth arrest and enhanced apoptosis, revealing a role for ATM in the mechanism that mediates sensitivity to temozolomide–olaparib. Interestingly, functional TP53 is required for efficacy of this treatment. In an in vivo model, coadministration of temozolomide–olaparib resulted in sustained xenograft regression.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0593hwp:master-id:clincanres;1078-0432.CCR-17-0593American Association for Cancer Research2017-11-15Personalized Medicine and Imaging232268756887http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6888?rss=1
Purpose: To validate the prognostic impact of combined expression levels of three markers (SPP1, RGS1, and NCOA3) in melanoma specimens from patients enrolled in the E1690 clinical trial of high-dose or low-dose IFNα-2b versus observation.

Experimental Design: Tissue was available from 248 patients. Marker expression was determined by digital imaging of immunohistochemically stained slides. The prognostic impact of each marker was first assessed by recording its expression value relative to the median. A multimarker index was then developed to combine marker expression levels by counting for each patient the number of markers with high expression. The impact of the multimarker index on relapse-free survival (RFS) and overall survival (OS) was assessed using Kaplan–Meier analysis, and both univariate and multivariate Cox regression analyses.

Results: By Kaplan–Meier analysis, high multimarker expression scores were significantly predictive of RFS (P < 0.001) and OS (P < 0.001). Stepwise multivariate Cox regression analysis with backward elimination that included routine clinical and histologic prognostic factors revealed high multimarker expression scores and tumor thickness as the only factors significantly and independently predicting RFS and OS. Stepwise multivariate Cox regression analyses that also included treatment type and number of positive lymph nodes generated identical results for both RFS and OS. In the molecularly defined low-risk subgroup, patients treated with high-dose IFN had a significantly improved RFS compared with patients in the other two subgroups (P < 0.05).

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-1317hwp:master-id:clincanres;1078-0432.CCR-17-1317American Association for Cancer Research2017-11-15Personalized Medicine and Imaging232268886892http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6893?rss=1
Purpose: The development of new treatments and their deployment in the clinic may be assisted by imaging methods that allow an early assessment of treatment response in individual patients. The C2A domain of Synaptotagmin-I (C2Am), which binds to the phosphatidylserine (PS) exposed by apoptotic and necrotic cells, has been developed as an imaging probe for detecting cell death. Multispectral optoacoustic tomography (MSOT) is a real-time and clinically applicable imaging modality that was used here with a near infrared (NIR) fluorophore-labeled C2Am to image tumor cell death in mice treated with a TNF-related apoptosis-inducing ligand receptor 2 (TRAILR2) agonist and with 5-fluorouracil (5-FU).

Experimental Design: C2Am was labeled with a NIR fluorophore and injected intravenously into mice bearing human colorectal TRAIL-sensitive Colo205 and TRAIL-resistant HT-29 xenografts that had been treated with a potent agonist of TRAILR2 and in Colo205 tumors treated with 5-FU.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-1029hwp:master-id:clincanres;1078-0432.CCR-17-1029American Association for Cancer Research2017-11-15Personalized Medicine and Imaging232268936903http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6904?rss=1
Purpose: To develop and validate a radiomics nomogram for the preoperative prediction of lymph node (LN) metastasis in bladder cancer.

Experimental Design: A total of 118 eligible bladder cancer patients were divided into a training set (n = 80) and a validation set (n = 38). Radiomics features were extracted from arterial-phase CT images of each patient. A radiomics signature was then constructed with the least absolute shrinkage and selection operator algorithm in the training set. Combined with independent risk factors, a radiomics nomogram was built with a multivariate logistic regression model. Nomogram performance was assessed in the training set and validated in the validation set. Finally, decision curve analysis was performed with the combined training and validation set to estimate the clinical usefulness of the nomogram.

Experimental Design: We imaged 10 female patients ages 48–81 years with malignant nonspecific breast cancer or invasive lobular carcinoma. Three healthy volunteers ages 31–36 years were also imaged. Fast-MSOT was based on unique single-frame-per-pulse (SFPP) image acquisition employed to improve the accuracy of spectral differentiation over using a small number of wavelengths. Breast tissue was illuminated at the 700–970 nm spectral range over 0.56 seconds total scan time. MSOT data were guided by ultrasonography and X-ray mammography or MRI.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-16-3200hwp:master-id:clincanres;1078-0432.CCR-16-3200American Association for Cancer Research2017-11-15Personalized Medicine and Imaging232269126922http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6923?rss=1
Purpose: Prostate cancer was recently classified to three clinically relevant subtypes (PCS) demarcated by unique pathway activation and clinical aggressiveness. In this preclinical study, we investigated molecular targets and therapeutics for PCS1, the most aggressive and lethal subtype, with no treatment options available in the clinic.

Experimental Design: We utilized the PCS1 gene set and our model of enzalutamide (ENZR) castration-resistant prostate cancer (CRPC) to identify targetable pathways and inhibitors for PCS1. The findings were evaluated in vitro and in the ENZR CRPC xenograft model in vivo.

Results: The results revealed that ENZR CRPC cells are enriched with PCS1 signature and that Forkhead box M1 (FOXM1) pathway is the central driver of this subtype. Notably, we identified Monensin as a novel FOXM1-binding agent that selectively targets FOXM1 to reverse the PCS1 signature and its associated stem-like features and reduces the growth of ENZR CRPC cells and xenograft tumors.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0901hwp:master-id:clincanres;1078-0432.CCR-17-0901American Association for Cancer Research2017-11-15Cancer Therapy: Preclinical232269236933http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6934?rss=1
Purpose: Chemoresistant ovarian cancers grow in suspension within the ascites fluid. To screen the effect of chemotherapeutics and biologics on resistant ovarian cancers with a personalized basis, we developed a 3D hanging drop spheroid platform.

Experimental Design: We initiated spheroids with primary aldehyde dehydrogenase–positive (ALDH+) CD133+ ovarian cancer stem cells (OvCSC) from different patient samples and demonstrated that stem cell progeny from harvested spheroids was similar to the primary tumor. OvCSC spheroids were utilized to initiate tumors in immunodeficient mice. Drug responses to cisplatin and ALDH-targeting compound or JAK2 inhibitor determined whether the OvCSC population within the spheroids could be targeted. Cells that escaped therapy were isolated and used to initiate new spheroids and model tumor reemergence in a personalized manner.

Results: OvCSC spheroids from different patients exhibited varying and personalized responses to chemotherapeutics. Xenografts were established from OvCSC spheroids, even with a single spheroid. Distinct responses to therapy were observed in distinct primary tumor xenografts similar to those observed in spheroids. Spheroids resistant to cisplatin/ALDH inhibitor therapy had persistent, albeit lower ALDH expression and complete loss of CD133 expression, whereas those resistant to cisplatin/JAK2 inhibitor therapy were enriched for ALDH+ cells.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0133hwp:master-id:clincanres;1078-0432.CCR-17-0133American Association for Cancer Research2017-11-15Cancer Therapy: Preclinical232269346945http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6946?rss=1
Purpose: Effective therapies for the majority of metastatic acral melanoma patients have not been established. Thus, we investigated genetic aberrations of CDK4 pathway in acral melanoma and evaluated the efficacy of CDK4/6 inhibitors in targeted therapy of acral melanoma.

Experimental Design: A total of 514 primary acral melanoma samples were examined for the copy number variations (CNV) of CDK4 pathway-related genes, including Cdk4, Ccnd1, and P16INK4a, by QuantiGenePlex DNA Assay. The sensitivity of established acral melanoma cell lines and patient-derived xenograft (PDX) containing typical CDK4 aberrations to CDK4/6 inhibitors was evaluated.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0070hwp:master-id:clincanres;1078-0432.CCR-17-0070American Association for Cancer Research2017-11-15Cancer Therapy: Preclinical232269466957http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6958?rss=1
Purpose: Glioblastoma (GBM) is a deadly brain tumor marked by dysregulated signaling and aberrant cell-cycle control. Molecular analyses have identified that the CDK4/6-Rb-E2F axis is dysregulated in about 80% of GBMs. Single-agent CDK4/6 inhibitors have failed to provide durable responses in GBM, suggesting a need to combine them with other agents. We investigate the efficacy of the combination of CDK4/6 inhibition and mTOR inhibition against GBM.

Experimental Design: Preclinical in vitro and in vivo assays using primary GBM cell lines were performed.

Results: We show that the CDK4/6 inhibitor palbociclib suppresses the activity of downstream mediators of the mTOR pathway, leading to rebound mTOR activation that can be blocked by the mTOR inhibitor everolimus. We further show that mTOR inhibition with everolimus leads to activation of the Ras mediator Erk that is reversible with palbociclib. The combined treatment strongly disrupts GBM metabolism, resulting in significant apoptosis. Further increasing the utility of the combination for brain cancers, everolimus significantly increases the brain concentration of palbociclib.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0803hwp:master-id:clincanres;1078-0432.CCR-17-0803American Association for Cancer Research2017-11-15Cancer Therapy: Preclinical232269586968http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6969?rss=1
Purpose:RUNX1-mutated (RUNX1mut) acute myeloid leukemia (AML) is associated with adverse outcome, highlighting the urgent need for a better genetic characterization of this AML subgroup and for the design of efficient therapeutic strategies for this disease. Toward this goal, we further dissected the mutational spectrum and gene expression profile of RUNX1mut AML and correlated these results to drug sensitivity to identify novel compounds targeting this AML subgroup.

Experimental Design: RNA-sequencing of 47 RUNX1mut primary AML specimens was performed and sequencing results were compared to those of RUNX1 wild-type samples. Chemical screens were also conducted using RUNX1mut specimens to identify compounds selectively affecting the viability of RUNX1mut AML.

Results: We show that samples with no remaining RUNX1 wild-type allele are clinically and genetically distinct and display a more homogeneous gene expression profile. Chemical screening revealed that most RUNX1mut specimens are sensitive to glucocorticoids (GCs) and we confirmed that GCs inhibit AML cell proliferation through their interaction with the glucocorticoid receptor (GR). We observed that specimens harboring RUNX1 mutations expected to result in low residual RUNX1 activity are most sensitive to GCs, and that coassociating mutations as well as GR levels contribute to GC sensitivity. Accordingly, acquired glucocorticoid sensitivity was achieved by negatively regulating RUNX1 expression in human AML cells.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-1259hwp:master-id:clincanres;1078-0432.CCR-17-1259American Association for Cancer Research2017-11-15Cancer Therapy: Preclinical232269696981http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6982?rss=1
Purpose: Despite favorable responses of chimeric antigen receptor (CAR)-engineered T-cell therapy in patients with hematologic malignancies, the outcome has been far from satisfactory in the treatment of solid tumors, partially owing to the development of an immunosuppressive tumor microenvironment. To overcome this limitation, we engineered CAR T cells secreting checkpoint inhibitors (CPI) targeting PD-1 (CAR.αPD1-T) and evaluated their efficacy in a human lung carcinoma xenograft mouse model.

Experimental Design: To evaluate the effector function and expansion capacity of CAR.αPD1-T cells in vitro, we measured the production of IFN and T-cell proliferation following antigen-specific stimulation. Furthermore, the antitumor efficacy of CAR.αPD1-T cells, CAR T cells, and CAR T cells combined with anti–PD-1 antibody was determined using a xenograft mouse model. Finally, the underlying mechanism was investigated by analyzing the expansion and functional capacity of TILs.

Results: Human anti–PD-1 CPIs secreted by CAR.αPD1-T cells efficiently bound to PD-1 and reversed the inhibitory effect of PD-1/PD-L1 interaction on T-cell function. PD-1 blockade by continuously secreted anti–PD-1 attenuated the inhibitory T-cell signaling and enhanced T-cell expansion and effector function both in vitro and in vivo. In the xenograft mouse model, we demonstrated that the secretion of anti–PD-1 enhanced the antitumor activity of CAR T cells and prolonged overall survival.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0867hwp:master-id:clincanres;1078-0432.CCR-17-0867American Association for Cancer Research2017-11-15Cancer Therapy: Preclinical232269826992http://clincancerres.aacrjournals.org/cgi/content/short/23/22/6993?rss=1
Purpose:KRAS-activating mutations are the most common oncogenic driver in non–small cell lung cancer (NSCLC), but efforts to directly target mutant KRAS have proved a formidable challenge. Therefore, multitargeted therapy may offer a plausible strategy to effectively treat KRAS-driven NSCLCs. Here, we evaluate the efficacy and mechanistic rationale for combining mTOR and WEE1 inhibition as a potential therapy for lung cancers harboring KRAS mutations.

Experimental Design: We investigated the synergistic effect of combining mTOR and WEE1 inhibitors on cell viability, apoptosis, and DNA damage repair response using a panel of human KRAS-mutant and wild type NSCLC cell lines and patient-derived xenograft cell lines. Murine autochthonous and human transplant models were used to test the therapeutic efficacy and pharmacodynamic effects of dual treatment.

Results: We demonstrate that combined inhibition of mTOR and WEE1 induced potent synergistic cytotoxic effects selectively in KRAS-mutant NSCLC cell lines, delayed human tumor xenograft growth and caused tumor regression in a murine lung adenocarcinoma model. Mechanistically, we show that inhibition of mTOR potentiates WEE1 inhibition by abrogating compensatory activation of DNA repair, exacerbating DNA damage in KRAS-mutant NSCLC, and that this effect is due in part to reduction in cyclin D1.

Experimental Design: We studied responses to various mono- and bifunctional alkylating agents in a genetically engineered mouse model for BRCA1/p53-mutant breast cancer. Because of the large intragenic deletion of the Brca1 gene, no restoration of BRCA1 function is possible, and therefore, no BRCA1-dependent acquired resistance occurs. To characterize the cell-cycle stage from which Brca1–/–;p53–/– mammary tumors arise after cisplatin treatment, we introduced the fluorescent ubiquitination-based cell-cycle indicator (FUCCI) construct into the tumor cells.

Results: Despite repeated sensitivity to the MTD of platinum drugs, the Brca1-mutated mammary tumors are not eradicated, not even by a frequent dosing schedule. We show that relapse comes from single-nucleated cells delaying entry into the S-phase. Such slowly cycling cells, which are present within the drug-naïve tumors, are enriched in tumor remnants. Using the FUCCI construct, we identified nonfluorescent G0-like cells as the population most tolerant to platinum drugs. Intriguingly, these cells are more sensitive to the DNA-crosslinking agent nimustine, resulting in an increased number of multinucleated cells that lack clonogenicity. This is consistent with our in vivo finding that the nimustine MTD, among several alkylating agents, is the most effective in eradicating Brca1-mutated mouse mammary tumors.

Experimental Design: To evaluate the potential role of immune cells in the development of resistance to VEGF blockade, we first established a preclinical model of adaptive resistance to anti-VEGF therapy. Additional in vitro and in vivo studies were carried out to characterize the role of macrophages in such resistance.

Results: Using murine cancer models of adaptive resistance to anti-VEGF antibody (AVA), we found a previously unrecognized role of macrophages in such resistance. Macrophages were actively recruited to the tumor microenvironment and were responsible for the emergence of AVA resistance. Depletion of macrophages following emergence of resistance halted tumor growth and prolonged survival of tumor-bearing mice. In a macrophage-deficient mouse model, resistance to AVA failed to develop, but could be induced by injection of macrophages. Downregulation of macrophage VEGFR-1 and VEGFR-3 expression accompanied upregulation of alternative angiogenic pathways, facilitating escape from anti-VEGF therapy.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0077hwp:master-id:clincanres;1078-0432.CCR-17-0077American Association for Cancer Research2017-11-15Cancer Therapy: Preclinical232270477058http://clincancerres.aacrjournals.org/cgi/content/short/23/22/7059?rss=1
Purpose: Bevacizumab, a humanized monoclonal antibody to VEGF, is used routinely in the treatment of patients with recurrent glioblastoma (GBM). However, very little is known regarding the effects of bevacizumab on the cells in the perivascular space in tumors.

Experimental Design: Established orthotopic xenograft and syngeneic models of GBM were used to determine entry of monoclonal anti-VEGF-A into, and uptake by cells in, the perivascular space. Based on the results, we examined CD133+ cells derived from GBM tumors in vitro. Bevacizumab internalization, trafficking, and effects on cell survival were analyzed using multilabel confocal microscopy, immunoblotting, and cytotoxicity assays in the presence/absence of inhibitors.

Results: In the GBM mouse models, administered anti-mouse-VEGF-A entered the perivascular tumor niche and was internalized by Sox2+/CD44+ tumor cells. In the perivascular tumor cells, bevacizumab was detected in the recycling compartment or the lysosomes, and increased autophagy was found. Bevacizumab was internalized rapidly by CD133+/Sox2+-GBM cells in vitro through macropinocytosis with a fraction being trafficked to a recycling compartment, independent of FcRn, and a fraction to lysosomes. Bevacizumab treatment of CD133+ GBM cells depleted VEGF-A and induced autophagy thereby improving cell survival. An inhibitor of lysosomal acidification decreased bevacizumab-induced autophagy and increased cell death. Inhibition of macropinocytosis increased cell death, suggesting macropinocytosis of bevacizumab promotes CD133+ cell survival.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0249hwp:master-id:clincanres;1078-0432.CCR-17-0249American Association for Cancer Research2017-11-15Biology of Human Tumors232270597071http://clincancerres.aacrjournals.org/cgi/content/short/23/22/7072?rss=1
Purpose: Current clinical parameters do not stratify indolent from aggressive prostate cancer. Aggressive prostate cancer, defined by the progression from localized disease to metastasis, is responsible for the majority of prostate cancer–associated mortality. Recent gene expression profiling has proven successful in predicting the outcome of prostate cancer patients; however, they have yet to provide targeted therapy approaches that could inhibit a patient's progression to metastatic disease.

Experimental Design: We have interrogated a total of seven primary prostate cancer cohorts (n = 1,900), two metastatic castration-resistant prostate cancer datasets (n = 293), and one prospective cohort (n = 1,385) to assess the impact of TOP2A and EZH2 expression on prostate cancer cellular program and patient outcomes. We also performed IHC staining for TOP2A and EZH2 in a cohort of primary prostate cancer patients (n = 89) with known outcome. Finally, we explored the therapeutic potential of a combination therapy targeting both TOP2A and EZH2 using novel prostate cancer–derived murine cell lines.

Results: We demonstrate by genome-wide analysis of independent primary and metastatic prostate cancer datasets that concurrent TOP2A and EZH2 mRNA and protein upregulation selected for a subgroup of primary and metastatic patients with more aggressive disease and notable overlap of genes involved in mitotic regulation. Importantly, TOP2A and EZH2 in prostate cancer cells act as key driving oncogenes, a fact highlighted by sensitivity to combination-targeted therapy.

Results: We found the interaction of MET with the adaptor protein GRB2 is necessary for oncogenic survival signaling by MET. MET-GRB2 complexes were identified only within MET-amplified PDX models and patient specimens but exhibit substantial variability. Lack of MET-GRB2 complexes was associated with lack of response to MET TKI in cell lines and PDX models. Presence of MET-GRB2 complexes can further subtype tumors with exon14 MET splice variants. Presence of these complexes correlated with response to crizotinib in one patient with exon14 MET lacking MET gene amplification.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-16-3006hwp:master-id:clincanres;1078-0432.CCR-16-3006American Association for Cancer Research2017-11-15Biology of Human Tumors232270847096http://clincancerres.aacrjournals.org/cgi/content/short/23/22/7097?rss=1
Purpose: Understanding tumor heterogeneity is an important challenge in current cancer research. Transcription and epigenetic profiling of cultured melanoma cells have defined at least two distinct cell phenotypes characterized by distinctive gene expression signatures associated with high or low/absent expression of microphthalmia-associated transcription factor (MITF). Nevertheless, heterogeneity of cell populations and gene expression in primary human tumors is much less well characterized.

Experimental Design: We performed single-cell gene expression analyses on 472 cells isolated from needle biopsies of 5 primary human melanomas, 4 superficial spreading, and one acral melanoma. The expression of MITF-high and MITF-low signature genes was assessed and compared to investigate intra- and intertumoral heterogeneity and correlated gene expression profiles.

Results: Single-cell gene expression analyses revealed varying degrees of intra- and intertumor heterogeneity conferred by the variable expression of distinct sets of genes in different tumors. Expression of MITF partially correlated with that of its known target genes, while SOX10 expression correlated best with PAX3 and ZEB2. Nevertheless, cells simultaneously expressing MITF-high and MITF-low signature genes were observed both by single-cell analyses and RNAscope.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0010hwp:master-id:clincanres;1078-0432.CCR-17-0010American Association for Cancer Research2017-11-15Biology of Human Tumors232270977107http://clincancerres.aacrjournals.org/cgi/content/short/23/22/7108?rss=1
Purpose: To investigate the role and the underlying mechanism of scaffold attachment factor B (SAFB) in the progression of colorectal cancer (CRC).

Experimental Design: SAFB expression was analyzed in the Cancer Outlier Profile Analysis of Oncomine and in 175 paraffin-embedded archived CRC tissues. Gene Ontology analyses were performed to explore the mechanism of SAFB in CRC progression. Western blot, RT-PCR, luciferase assay, and chromatin immunoprecipitation (ChIP) were used to detect the regulation of transforming growth factor-β–activated kinase 1 (TAK1) and NF-B signaling by SAFB. The role of SAFB in invasion, metastasis, and angiogenesis was investigated using in vitro and in vivo assays. The relationship between SAFB and TAK1 was analyzed in CRC tissues.

Results: SAFB was downregulated in CRC tissues, and low expression of SAFB was significantly associated with an aggressive phenotype and poorer survival of CRC patients. The downregulation of SAFB activated NF-B signaling by targeting the TAK1 promoter. Ectopic expression of SAFB inhibited the development of aggressive features and metastasis of CRC cells both in vitro and in vivo. The overexpression of TAK1 could rescue the aggressive features in SAFB-overexpressed cells. Furthermore, the expression of SAFB in CRC tissues was negatively correlated with the expression of TAK1- and NF-B–related genes.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-0747hwp:master-id:clincanres;1078-0432.CCR-17-0747American Association for Cancer Research2017-11-15Biology of Human Tumors232271087118http://clincancerres.aacrjournals.org/cgi/content/short/23/22/7119?rss=1
Purpose: B-cell lymphomas must acquire resistance to apoptosis during their development. We recently discovered BCLW, an antiapoptotic BCL2 family member thought only to contribute to spermatogenesis, was overexpressed in diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma. To gain insight into the contribution of BCLW to B-cell lymphomas and its potential to confer resistance to BCL2 inhibitors, we investigated the expression of BCLW and the other antiapoptotic BCL2 family members in six different B-cell lymphomas.

Experimental Design: We performed a large-scale gene expression analysis of datasets comprising approximately 2,300 lymphoma patient samples, including non-Hodgkin and Hodgkin lymphomas as well as indolent and aggressive lymphomas. Data were validated experimentally with qRT-PCR and IHC.

Results: We report BCLW is significantly overexpressed in aggressive and indolent lymphomas, including DLBCL, Burkitt, follicular, mantle cell, marginal zone, and Hodgkin lymphomas. Notably, BCLW was preferentially overexpressed over that of BCL2 and negatively correlated with BCL2 in specific lymphomas. Unexpectedly, BCLW was overexpressed as frequently as BCL2 in follicular lymphoma. Evaluation of all five antiapoptotic BCL2 family members in six types of B-cell lymphoma revealed that BCL2, BCLW, and BCLX were consistently overexpressed, whereas MCL1 and A1 were not. In addition, individual lymphomas frequently overexpressed more than one antiapoptotic BCL2 family member.

]]>2017-11-14T21:05:52-08:00info:doi/10.1158/1078-0432.CCR-17-1144hwp:master-id:clincanres;1078-0432.CCR-17-1144American Association for Cancer Research2017-11-15Biology of Human Tumors232271197129http://clincancerres.aacrjournals.org/cgi/content/short/23/22/7130?rss=1
Purpose: Choriocarcinoma (CC) is the most malignant gestational trophoblastic disease that often develops from complete hydatidiform moles (CHM). Neither the mechanism of CC development nor its progression is yet characterized. We recently identified endocrine gland–derived vascular endothelial growth factor (EG-VEGF) as a novel key placental growth factor that controls trophoblast proliferation and invasion. EG-VEGF acts via two receptors, PROKR1 and PROKR2. Here, we demonstrate that EG-VEGF receptors can be targeted for CC therapy.

Experimental Design: Three approaches were used: (i) a clinical investigation comparing circulating EG-VEGF in control (n = 20) and in distinctive CHM (n = 38) and CC (n = 9) cohorts, (ii) an in vitro study investigating EG-VEGF effects on the CC cell line JEG3, and (iii) an in vivo study including the development of a novel CC mouse model, through a direct injection of JEG3-luciferase into the placenta of gravid SCID-mice.

Results: Both placental and circulating EG-VEGF levels were increased in CHM and CC (x5) patients. EG-VEGF increased JEG3 proliferation, migration, and invasion in two-dimensional (2D) and three-dimensional (3D) culture systems. JEG3 injection in the placenta caused CC development with large metastases compared with their injection into the uterine horn. Treatment of the animal model with EG-VEGF receptor's antagonists significantly reduced tumor development and progression and preserved pregnancy. Antibody-array and immunohistological analyses further deciphered the mechanism of the antagonist's actions.

Experimental Design: Identification of differentially methylated regions (DMR) was performed with bumphunter on "The Cancer Genome Atlas (TCGA)" dataset, and clinical utility was assessed using quantitative methylation-specific PCR assay in multiple sets of primary NSCLC and body fluids that included serum, pleural effusion, and ascites samples.

Results: A methylation panel of 6 genes (CDO1, HOXA9, AJAP1, PTGDR, UNCX, and MARCH11) was selected from TCGA dataset. Promoter methylation of the gene panel was detected in 92.2% (83/90) of the training cohort with a specificity of 72.0% (18/25) and in 93.0% (40/43) of an independent cohort of stage IA primary NSCLC. In serum samples from the later 43 stage IA subjects and population-matched 42 control subjects, the gene panel yielded a sensitivity of 72.1% (31/41) and specificity of 71.4% (30/42). Similar diagnostic accuracy was observed in pleural effusion and ascites samples. A prognostic risk category based on the methylation status of CDO1, HOXA9, PTGDR, and AJAP1 refined the risk stratification for outcomes as an independent prognostic factor for an early-stage disease. Moreover, the paralog group for HOXA9, predominantly overexpressed in subjects with HOXA9 methylation, showed poor outcomes.

Experimental Design: Dose escalation with a sequential 3+3 design was performed in five steps at the 0.1, 1, 2, 5, and 10 mg/kg dose levels (N = 26). ARGX-110 was administered intravenously every 3 weeks until progression or intolerable toxicity. Dose-limiting toxicity was evaluated in the 21 days following the first ARGX-110 administration (Cycle 1). Samples for pharmacokinetics and pharmacodynamics were collected.

Results: Dose-limiting toxicity was not observed and the maximum tolerated dose was not reached. ARGX-110 was generally well tolerated, with no dose-related increase in treatment-emergent adverse events (TEAE). The most common TEAE were fatigue and drug related infusion-related reactions (IRR). Of the 20 SAEs reported, five events, all IRRs, were considered related to ARGX-110. ARGX-110 demonstrates dose proportionality over the dose range 1 to 10 mg/kg, but not at 0.1 mg/kg and a terminal half-life of 10 to 13 days. The best overall response was stable disease (14/26) in all 26 evaluable patients with various malignancies and the mean duration of treatment was 15 weeks. No dose–response related antitumor activity was observed, but biomarker readouts provided signs of biological activity, particularly in patients with hematologic malignancies.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0613hwp:master-id:clincanres;1078-0432.CCR-17-0613American Association for Cancer Research2017-11-01Cancer Therapy: Clinical232164116420http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6421?rss=1
Purpose: A phase I trial of veliparib in combination with topotecan plus carboplatin (T+C) demonstrated a 33% objective response rate in patients with hematological malignancies. The objective is to perform exposure–response analysis to inform the phase II trial design.

Experimental Design: Pharmacokinetic, efficacy, and safety data from 95 patients, who were administered 10 to 100 mg b.i.d. doses of veliparib for either 8, 14, or 21 days with T+C, were utilized for exposure–efficacy (objective response and overall survival) and exposure–safety (≥grade 3 mucositis) analysis. Multivariate cox proportional hazards and logistic regression analyses were conducted. The covariates evaluated were disease status, duration of treatment, and number of prior therapies.

Results: The odds of having objective response were 1.08-fold with 1,000 ng/hr/mL increase in AUC, 1.8-fold with >8 days treatment, 2.8-fold in patients with myeloproliferative neoplasms (MPN), and 0.5-fold with ≥2 prior therapies. Based on analysis of overall survival, hazard of death decreased by 1.5% for 1,000 ng/hr/mL increase in AUC, 39% with >8 days treatment, 44% in patients with MPN, while increased by 19% with ≥2 prior therapies. The odds of having ≥grade 3 mucositis increased by 29% with 1,000 ng.h/mL increase in AUC.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0143hwp:master-id:clincanres;1078-0432.CCR-17-0143American Association for Cancer Research2017-11-01Cancer Therapy: Clinical232164216429http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6430?rss=1
Purpose: Azacitidine (AZA) is a novel therapeutic option in older patients with acute myeloid leukemia (AML), but its rational utilization is compromised by the fact that neither the determinants of clinical response nor its mechanism of action are defined. Co-administration of histone deacetylase inhibitors, such as vorinostat (VOR), is reported to improve the clinical activity of AZA, but this has not been prospectively studied in patients with AML.

Experimental Design: We compared outcomes in 259 adults with AML (n = 217) and MDS (n = 42) randomized to receive either AZA monotherapy (75 mg/m2x 7 days every 28 days) or AZA combined with VOR 300 mg twice a day on days 3 to 9 orally. Next-generation sequencing was performed in 250 patients on 41 genes commonly mutated in AML. Serial immunophenotyping of progenitor cells was performed in 47 patients.

Results: Co-administration of VOR did not increase the overall response rate (P = 0.84) or overall survival (OS; P = 0.32). Specifically, no benefit was identified in either de novo or relapsed AML. Mutations in the genes CDKN2A (P = 0.0001), IDH1 (P = 0.004), and TP53 (P = 0.003) were associated with reduced OS. Lymphoid multipotential progenitor populations were greatly expanded at diagnosis and although reduced in size in responding patients remained detectable throughout treatment.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0379hwp:master-id:clincanres;1078-0432.CCR-17-0379American Association for Cancer Research2017-11-01Cancer Therapy: Clinical232164416449http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6450?rss=1
Purpose: Research biopsies are frequently incorporated within clinical trials in oncology and are often a mandatory requirement for trial enrollment. However, limited information is available regarding the extent and completeness of research biopsy reporting.

Experimental Design: We identified a cohort of therapeutic clinical trials where research biopsies were performed between January 2005 and October 2010 from an IR database at our institution. Clinical trial protocols were compared with the highest level of corresponding publication as a manuscript or registry report.

Results: A total of 866 research biopsies were performed across 46 clinical trials, with a median of 8 patients biopsied/trial and 19 biopsies collected/trial. After a median follow-up time of 4.3 years from trial completion, 36 of 46 trials (78%) reported trial results: published manuscripts (n = 35), or registry report (n = 1). A total of 635 conducted biopsies were reported in 18 of the 46 trials (39%). Six (33%) of these 18 trials underreported the number of biopsies performed. Of 33 trials with mandatory research biopsies, 13 (39%) trials reported on these biopsies. Biopsy complications occurred in 8 trials [n = 39 patients, 6 grade 3/4 adverse events (AE)] but only 1 trial reported these. Factors associated with biopsy reporting included a larger number of biopsies (P ≤ 0.001) and serial biopsies (P < 0.001). Twelve of 16 (75%) trials with >12 biopsies performed reported on these biopsies compared with only 20% (6/30) that performed ≤12 biopsies.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-1449hwp:master-id:clincanres;1078-0432.CCR-17-1449American Association for Cancer Research2017-11-01Cancer Therapy: Clinical232164506457http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6458?rss=1
Purpose: Endometrial cancer (EC) diagnosis relies on the observation of tumor cells in endometrial biopsies obtained by aspiration (i.e., uterine aspirates), but it is associated with 22% undiagnosed patients and up to 50% of incorrectly assigned EC histotype and grade. We aimed to identify biomarker signatures in the fluid fraction of these biopsies to overcome these limitations.

Experimental Design: The levels of 52 proteins were measured in the fluid fraction of uterine aspirates from 116 patients by LC-PRM, the latest generation of targeted mass-spectrometry acquisition. A logistic regression model was used to assess the power of protein panels to differentiate between EC and non-EC patients and between EC histologic subtypes. The robustness of the panels was assessed by the "leave-one-out" cross-validation procedure performed within the same cohort of patients and an independent cohort of 38 patients.

Results: The levels of 28 proteins were significantly higher in patients with EC (n = 69) compared with controls (n = 47). The combination of MMP9 and KPYM exhibited 94% sensitivity and 87% specificity for detecting EC cases. This panel perfectly complemented the standard diagnosis, achieving 100% of correct diagnosis in this dataset. Nine proteins were significantly increased in endometrioid EC (n = 49) compared with serous EC (n = 20). The combination of CTNB1, XPO2, and CAPG achieved 95% sensitivity and 96% specificity for the discrimination of these subtypes.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0474hwp:master-id:clincanres;1078-0432.CCR-17-0474American Association for Cancer Research2017-11-01Personalized Medicine and Imaging232164586467http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6468?rss=1
Background: Breast cancer patients who do not respond to neoadjuvant therapy have a poor prognosis. There is a pressing need for novel targets and models for preclinical testing. Here we report characterization of breast cancer patient-derived xenografts (PDX) largely generated from residual tumors following neoadjuvant chemotherapy.

Experimental Design: PDXs were derived from surgical samples of primary or locally recurrent tumors. Normal and tumor DNA sequencing, RNASeq, and reverse phase protein arrays (RPPA) were performed. Phenotypic profiling was performed by determining efficacy of a panel of standard and investigational agents.

Results: Twenty-six PDXs were developed from 25 patients. Twenty-two were generated from residual disease following neoadjuvant chemotherapy, and 24 were from triple-negative breast cancer (TNBC). These PDXs harbored a heterogeneous set of genomic alterations and represented all TNBC molecular subtypes. On RPPA, PDXs varied in extent of PI3K and MAPK activation. PDXs also varied in their sensitivity to chemotherapeutic agents. PI3K, mTOR, and MEK inhibitors repressed growth but did not cause tumor regression. The PARP inhibitor talazoparib caused dramatic regression in five of 12 PDXs. Notably, four of five talazoparib-sensitive models did not harbor germline BRCA1/2 mutations, but several had somatic alterations in homologous repair pathways, including ATM deletion and BRCA2 alterations.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0615hwp:resource-id:clincanres;23/21/6468American Association for Cancer Research2017-11-01Personalized Medicine and Imaging232164686477http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6478?rss=1
Purpose: Survival of acute leukemia (AL) patients following umbilical cord blood transplantation (UCBT) is dependent on an array of individual features. Integrative models for risk assessment are lacking. We sought to develop a scoring system for prediction of overall survival (OS) and leukemia-free survival (LFS) at 2 years following UCBT in AL patients.

Experimental Design: The study cohort included 3,140 pediatric and adult AL UCBT patients from the European Society of Blood and Marrow Transplantation and Eurocord registries. Patients received single or double cord blood units. The dataset was geographically split into a derivation (n = 2,362, 65%) and validation set (n = 778, 35%). Top predictors of OS were identified using the Random Survival Forest algorithm and introduced into a Cox regression model, which served for the construction of the UCBT risk score.

Results: The score includes nine variables: disease status, diagnosis, cell dose, age, center experience, cytomegalovirus serostatus, degree of HLA mismatch, previous autograft, and anti-thymocyte globulin administration. Over the validation set an increasing score was associated with decreasing probabilities for 2 years OS and LFS, ranging from 70.21% [68.89–70.71, 95% confidence interval (CI)] and 64.76% (64.33–65.86, 95% CI) to 14.78% (10.91–17.41) and 18.11% (14.40–22.30), respectively. It stratified patients into six distinct risk groups. The score's discrimination (AUC) over multiple imputations of the validation set was 68.76 (68.19–69.04, range) and 65.78 (65.20–66.28) for 2 years OS and LFS, respectively.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0489hwp:master-id:clincanres;1078-0432.CCR-17-0489American Association for Cancer Research2017-11-01Personalized Medicine and Imaging232164786486http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6487?rss=1
Purpose: Targeted agents and immunotherapies promise to transform the treatment of metastatic bladder cancer, but therapy selection will depend on practical tumor molecular stratification. Circulating tumor DNA (ctDNA) is established in several solid malignancies as a minimally invasive tool to profile the tumor genome in real-time, but is critically underexplored in bladder cancer.

Results: The majority of patients with metastasis, but only 14% of patients with localized disease, had ctDNA proportions above 2% of total cfDNA (median 16.5%, range 3.9%–72.6%). Twelve percent of estimable samples had evidence of genome hypermutation. We reveal an aggressive mutational landscape in metastatic bladder cancer with 95% of patients harboring deleterious alterations to TP53, RB1, or MDM2, and 70% harboring a mutation or disrupting rearrangement affecting chromatin modifiers such as ARID1A. Targetable alterations in MAPK/ERK or PI3K/AKT/mTOR pathways were robustly detected, including amplification of ERBB2 (20% of patients) and activating hotspot mutations in PIK3CA (20%), with the latter mutually exclusive to truncating mutations in TSC1. A novel FGFR3 gene fusion was identified in consecutive samples from one patient.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-1140hwp:master-id:clincanres;1078-0432.CCR-17-1140American Association for Cancer Research2017-11-01Personalized Medicine and Imaging232164876497http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6498?rss=1
Purpose: Late-stage, unresectable pancreatic ductal adenocarcinoma (PDAC) is largely resistant to chemotherapy and consequently has a very poor 5-year survival rate of <5%. The ability to assess the efficacy of a treatment soon after its initiation would enable rapid switching to potentially more effective therapies if the current treatment is found to be futile. We have evaluated the ability of the PET imaging agent, 89Zr-anti-H2AX-TAT, to monitor DNA damage in response to fluorouracil (5-FU), gemcitabine, or capecitabine treatment in a mouse model of pancreatic cancer. We have also compared the utility of this approach against the standard clinical PET radiotracer, 18F-FDG.

Experimental Design: C57BL/6 mice bearing subcutaneous pancreatic cancer (KPC; B8484) allografts were treated with 5-FU, gemcitabine, or capecitabine. Therapeutic response was monitored by PET and ex vivo biodistribution experiments using either 89Zr-anti-H2AX-TAT or 18F-FDG as imaging agents. To further examine the effect of therapeutic response upon uptake of these imaging agents, IHC analysis of harvested tumor allograft tissue was also performed.

Results: Accumulation of 89Zr-anti-H2AX-TAT in the tumors of mice that received chemotherapy was higher compared with vehicle-treated mice and was shown to be specifically mediated by H2AX. In contrast, 18F-FDG did not provide useful indications of therapeutic response.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0664hwp:master-id:clincanres;1078-0432.CCR-17-0664American Association for Cancer Research2017-11-01Personalized Medicine and Imaging232164986504http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6505?rss=1
Purpose: To determine whether markers of healthy breast stroma are able to select a subgroup of patients at low risk of death or metastasis from patients considered at high risk according to routine markers of the tumor.

Experimental Design: Patients with ER+/HER2– breast cancer were consecutively included for retrospective analysis. The contralateral parenchyma was segmented automatically on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), where upon the average of the top-10% late enhancement was calculated. This contralateral parenchymal enhancement (CPE) was analyzed with respect to routine prognostic models and molecular assays (Nottingham Prognostic Index, Dutch clinical chemotherapy-selection guidelines, 70-gene signature, and 21-gene recurrence score). CPE was split in tertiles and tested for overall and distant disease-free survival. CPE was adjusted for patient and tumor characteristics, as well as systemic therapy, using inverse probability weighting (IPW). Subanalyses were performed in patients at high risk according to prognostic models and molecular assays.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0176hwp:master-id:clincanres;1078-0432.CCR-17-0176American Association for Cancer Research2017-11-01Personalized Medicine and Imaging232165056515http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6516?rss=1
Purpose: The high affinity receptor 1 (NTSR1) and its agonist, neurotensin (NTS), are correlated with tumor cell aggressiveness in most solid tumors. As chemoresistance and tumor aggressiveness are often related, we decided to study the role of the NTSR1 complex within platinum-based chemotherapy responses. In an ovarian model, we studied carboplatin because it is the main standard of care for ovarian cancer.

Experimental Design: Experimental tumors and in vitro studies were performed using SKOV3 and A2780 cells treated with carboplatin, with or without a very specific NTSR1 antagonist, SR48692. We measured the effects of these treatments on cell apoptosis and apoptosis-related proteins, platinum accumulation in the cell and nucleus, and the expression and localization of platinum transporters. NTS and NTSR1 labeling was measured in patients with ovarian cancer.

Results: SR48692 enhanced the response to carboplatin in ovarian cancer cells and experimental tumors. When SR48692 is combined with carboplatin, we noted a major improvement of platinum-induced DNA damage and cell death, as well as a decrease in tumor growth. The relationship of these results to clinical studies was made by the detection of NTS and NTSR1 in 72% and 74% of ovarian cancer, respectively. Furthermore, in a large series of high-grade ovarian cancer, NTSR1 mRNA was shown to correlate with higher stages and platinum resistance.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0861hwp:master-id:clincanres;1078-0432.CCR-17-0861American Association for Cancer Research2017-11-01Cancer Therapy: Preclinical232165166528http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6529?rss=1
Purpose: A hallmark of neoplasia is increased ribosome biogenesis, and targeting this process with RNA polymerase I (Pol I) inhibitors has shown some efficacy. We examined the contribution and potential targeting of ribosomal machinery in chemotherapy-resistant and -sensitive models of ovarian cancer.

Experimental Design: Pol I machinery expression was examined, and subsequently targeted with the Pol I inhibitor CX-5461, in ovarian cancer cell lines, an immortalized surface epithelial line, and patient-derived xenograft (PDX) models with and without chemotherapy. Effects on viability, Pol I occupancy of rDNA, ribosomal content, and chemosensitivity were examined.

Results: In PDX models, ribosomal machinery components were increased in chemotherapy-treated tumors compared with controls. Thirteen cell lines were sensitive to CX-5461, with IC50s 25 nmol/L–2 μmol/L. Interestingly, two chemoresistant lines were 10.5- and 5.5-fold more sensitive than parental lines. CX-5461 induced DNA damage checkpoint activation and G2–M arrest with increased H2AX staining. Chemoresistant cells had 2- to 4-fold increased rDNA Pol I occupancy and increased rRNA synthesis, despite having slower proliferation rates, whereas ribosome abundance and translational efficiency were not impaired. In five PDX models treated with CX-5461, one showed a complete response, one a 55% reduction in tumor volume, and one maintained stable disease for 45 days.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0282hwp:master-id:clincanres;1078-0432.CCR-17-0282American Association for Cancer Research2017-11-01Cancer Therapy: Preclinical232165296540http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6541?rss=1
Purpose: The cure rate for patients with advanced head and neck squamous cell carcinoma (HNSCC) remains poor due to resistance to standard therapy primarily consisting of chemoradiation. As mutation of TP53 in HNSCC occurs in 60% to 80% of non–HPV-associated cases and is in turn associated with resistance to these treatments, more effective therapies are needed. In this study, we evaluated the efficacy of a regimen combining vorinostat and AZD1775 in HNSCC cells with a variety of p53 mutations.

Experimental Design: Clonogenic survival assays and an orthotopic mouse model of oral cancer were used to examine the in vitro and in vivo sensitivity of high-risk mutant p53 HNSCC cell lines to vorinostat in combination with AZD1775. Cell cycle, replication stress, homologous recombination (HR), live cell imaging, RNA sequencing, and apoptosis analyses were performed to dissect molecular mechanisms.

Results: We found that vorinostat synergizes with AZD1775 in vitro to inhibit growth of HNSCC cells harboring high-risk mutp53. These drugs interact synergistically to induce DNA damage, replication stress associated with impaired Rad51-mediated HR through activation of CDK1, and inhibition of Chk1 phosphorylation, culminating in an early apoptotic cell death during the S-phase of the cell cycle. The combination of vorinostat and AZD1775 inhibits tumor growth and angiogenesis in vivo in an orthotopic mouse model of oral cancer and prolongs animal survival.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0947hwp:master-id:clincanres;1078-0432.CCR-17-0947American Association for Cancer Research2017-11-01Cancer Therapy: Preclinical232165416554http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6555?rss=1
Purpose: Our previous screening efforts found that inhibition of PAPSS1 increases the potency of DNA-damaging agents in non–small cell lung cancer (NSCLC) cell lines. Here, we explored the clinical relevance of PAPSS1 and further investigated it as a therapeutic target in preclinical model systems.

Experimental Design: PAPSS1 expression and cisplatin IC50 values were assessed in 52 lung adenocarcinoma cell lines. Effects of PAPSS1 inhibition on A549 cisplatin sensitivity under hypoxic and starvation conditions, in 3D spheroids, as well as in zebrafish and mouse xenografts, were evaluated. Finally, the association between PAPSS1 expression levels and survival in patients treated with standard chemotherapy was assessed.

Results: Our results show a positive correlation between low PAPSS1 expression and increased cisplatin sensitivity in lung adenocarcinoma. In vitro, the potentiation effect was greatest when A549 cells were serum-starved under hypoxic conditions. When treated with low-dose cisplatin, PAPSS1-deficient A549 spheroids showed a 58% reduction in size compared with control cells. In vivo, PAPSS1 suppression and low-dose cisplatin treatment inhibited proliferation of lung tumor cells in zebrafish xenografts and significantly delayed development of subcutaneous tumors in mice. Clinical data suggest that NSCLC and ovarian cancer patients with low PAPSS1 expression survive longer following platinum-based chemotherapy.

]]>2017-10-31T21:05:54-07:00info:doi/10.1158/1078-0432.CCR-17-0700hwp:master-id:clincanres;1078-0432.CCR-17-0700American Association for Cancer Research2017-11-01Cancer Therapy: Preclinical232165556566http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6567?rss=1
Purpose: The mechanisms accounting for anticancer activity of AZD9291 (osimertinib or TAGRISSO), an approved third-generation EGFR inhibitor, in EGFR-mutant non–small cell lung cancer (NSCLC) cells and particularly for the subsequent development of acquired resistance are unclear and thus are the focus of this study.

Experimental Design: AZD9219-resistant cell lines were established by exposing sensitive cell lines to AZD9291. Protein alterations were detected with Western blotting. Apoptosis was measured with annexin V/flow cytometry. Growth-inhibitory effects of tested drugs were evaluated in vitro with cell number estimation and colony formation assay and in vivo with mouse xenograft models. Protein degradation was determined by comparing protein half-lives and inhibiting proteasome. Gene knockdown were achieved with siRNA or shRNA.

Results: AZD9291 potently induced apoptosis in EGFR-mutant NSCLC cell lines, in which ERK phosphorylation was suppressed accompanied with Bim elevation and Mcl-1 reduction likely due to enhanced Mcl-1 degradation and increased Bim stability. Blocking Bim elevation by gene knockdown or enforcing Mcl-1 expression attenuated or abolished AZD9291-induced apoptosis. Moreover, AZD9291 lost its ability to modulate Bim and Mcl-1 levels in AZD9291-resistant cell lines. The combination of a MEK inhibitor with AZD9291 restores the sensitivity of AZD9291-resistant cells including those with C797S mutation to undergo apoptosis and growth regression in vitro and in vivo.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-1574hwp:master-id:clincanres;1078-0432.CCR-17-1574American Association for Cancer Research2017-11-01Cancer Therapy: Preclinical232165676579http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6580?rss=1
Purpose: Activation of the PI3K pathway occurs in over 40% of bladder urothelial cancers. The aim of this study is to determine the therapeutic potential, the underlying action, and the resistance mechanisms of drugs targeting the PI3K pathway.

Experimental Design: Urothelial cancer cell lines and patient-derived xenografts (PDXs) were analyzed for alterations of the PI3K pathway and for their sensitivity to the small-molecule inhibitor pictilisib alone and in combination with cisplatin and/or gemcitabine. Potential predictive biomarkers for pictilisib were evaluated, and RNA sequencing was performed to explore drug resistance mechanisms.

Results: The bladder cancer cell line TCCSUP, which harbors a PIK3CA E545K mutation, was sensitive to pictilisib compared to cell lines with wild-type PIK3CA. Pictilisib exhibited stronger antitumor activity in bladder cancer PDX models with PI3KCA H1047R mutation or amplification than the control PDX model. Pictilisib synergized with cisplatin and/or gemcitabine in vitro, significantly delayed tumor growth, and prolonged survival compared with single-drug treatment in the PDX models. The phosphorylation of ribosomal protein S6 correlated with response to pictilisib both in vitro and in vivo, and could potentially serve as a biomarker to predict response to pictilisib. Pictilisib activated the compensatory MEK/ERK pathway that likely contributed to pictilisib resistance, which was reversed by cotreatment with the RAF inhibitor sorafenib. RNA sequencing of tumors resistant to treatment suggested that LSP1 downregulation correlated with drug resistance.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-0033hwp:master-id:clincanres;1078-0432.CCR-17-0033American Association for Cancer Research2017-11-01Cancer Therapy: Preclinical232165806591http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6592?rss=1
Purpose: Prior clinical trials evaluating cisplatin for non–muscle-invasive bladder cancer (NMIBC) were stopped due to local and systemic toxicity. Currently, there is still a need for improved intravesical therapies, and nanoparticle-based CDDP may be efficacious without the toxicity of free cisplatin observed in the past.

Experimental Design: Cisplatin nanoparticles (CDDP NPs) were developed using biocompatible poly(l-aspartic acid sodium salt; PAA), both with and without low and high grafting density of methoxy-polyethylene glycol (PEG). In vitro cytotoxicity studies confirmed activity of CDDP NPs and CDDP solution against a papillary bladder cancer cell line. Local toxicity was assessed by three weekly intravesical administrations of CDDP formulations. CDDP NPs and CDDP solution were evaluated for bladder absorption in murine models 1 and 4 hours after intravesical administration. In vivo efficacy was evaluated in an immunocompetent carcinogen model of NMIBC.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-1082hwp:master-id:clincanres;1078-0432.CCR-17-1082American Association for Cancer Research2017-11-01Cancer Therapy: Preclinical232165926601http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6602?rss=1
Purpose: The search for new drugs that control the continuous relapses of multiple myeloma is still required. Here, we report for the first time the potent antimyeloma activity of amiloride, an old potassium-sparing diuretic approved for the treatment of hypertension and edema due to heart failure.

Experimental Design: Myeloma cell lines and primary samples were used to evaluate cytotoxicity of amiloride. In vivo studies were carried out in a xenograft mouse model. The mechanisms of action were investigated using RNA-Seq experiments, qRT-PCR, immunoblotting, and immunofluorescence assays.

Results: Amiloride-induced apoptosis was observed in a broad panel of multiple myeloma cell lines and in a xenograft mouse model. Moreover, amiloride also had a synergistic effect when combined with dexamethasone, melphalan, lenalidomide, and pomalidomide. RNA-Seq experiments showed that amiloride not only significantly altered the level of transcript isoforms and alternative splicing events, but also deregulated the spliceosomal machinery. In addition, disruption of the splicing machinery in immunofluorescence studies was associated with the inhibition of myeloma cell viability after amiloride exposure. Although amiloride was able to induce apoptosis in myeloma cells lacking p53 expression, activation of p53 signaling was observed in wild-type and mutated TP53 cells after amiloride exposure. On the other hand, we did not find a significant systemic toxicity in mice treated with amiloride.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-0678hwp:master-id:clincanres;1078-0432.CCR-17-0678American Association for Cancer Research2017-11-01Cancer Therapy: Preclinical232166026615http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6616?rss=1
Purpose: Camelid single-domain antibody-fragments (sdAb) have beneficial pharmacokinetic properties, and those targeted to HER2 can be used for imaging of HER2-overexpressing cancer. Labeled with a therapeutic radionuclide, they may be used for HER2-targeted therapy. Here, we describe the generation of a 131I-labeled sdAb as a theranostic drug to treat HER2-overexpressing cancer.

Experimental Design: Anti-HER2 sdAb 2Rs15d was labeled with 131I using [131I]SGMIB and evaluated in vitro. Biodistribution was evaluated in two HER2+ murine xenograft models by micro-SPECT/CT imaging and at necropsy, and under challenge with trastuzumab and pertuzumab. The therapeutic potential of [131I]SGMIB-2Rs15d was investigated in two HER2+ tumor mouse models. A single-dose toxicity study was performed in mice using unlabeled [127I]SGMIB-sdAb at 1.4 mg/kg. The structure of the 2Rs15d–HER2 complex was determined by X-ray crystallography.

Results: [131I]SGMIB-2Rs15d bound specifically to HER2+ cells (Kd = 4.74 ± 0.39 nmol/L). High and specific tumor uptake was observed in both BT474/M1 and SKOV-3 tumor xenografted mice and surpassed kidney levels by 3 hours. Extremely low uptake values were observed in other normal tissues at all time points. The crystal structure revealed that 2Rs15d recognizes HER2 Domain 1, consistent with the lack of competition with trastuzumab and pertuzumab observed in vivo. [131I]SGMIB-2Rs15d alone, or in combination with trastuzumab, extended median survival significantly. No toxicity was observed after injecting [127I]SGMIB-2Rs15d.

Experimental Design: Using an orthotopic xenograft model and modulating p53 levels, we investigated the antitumor effects of the mTORC1 inhibitor temsirolimus in neuroblastoma expressing normal, decreased, or mutant p53, both as single agent and in combination with first- and second-generation MDM2 inhibitors to reactivate p53.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-0668hwp:master-id:clincanres;1078-0432.CCR-17-0668American Association for Cancer Research2017-11-01Biology of Human Tumors232166296639http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6640?rss=1
Purpose: Glioma-initiating cells (GIC) are glioma stem–like cells that contribute to glioblastoma (GBM) development, recurrence, and resistance to chemotherapy and radiotherapy. They have recently become the focus of novel treatment strategies. Cyclophilin A (CypA) is a cytosolic protein that belongs to the peptidyl–prolyl isomerase (PPIase) family and the major intracellular target of the immunosuppressive drug cyclosporin A (CsA). In this study, we investigate the functions of CypA and its mechanism of action in GICs' development.

Experimental Design: We analyzed differences in CypA expression between primary tumors and neurospheres from the GDS database, both before and after GIC differentiation. A series of experiments was conducted to investigate the role of CypA in GIC stemness, self-renewal, proliferation, radiotherapy resistance, and mechanism. We then designed glutathione S-transferase (GST) pulldown and coimmunoprecipitation assays to detect signaling activity.

Results: In this study, we demonstrated that CypA promotes GIC stemness, self-renewal, proliferation, and radiotherapy resistance. Mechanistically, we found that CypA binds β-catenin and is recruited to Wnt target gene promoters. By increasing the interaction between β-catenin and TCF4, CypA enhances transcriptional activity.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-0774hwp:master-id:clincanres;1078-0432.CCR-17-0774American Association for Cancer Research2017-11-01Biology of Human Tumors232166406649http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6650?rss=1
Purpose: Indoleamine 2,3 dioxygenase 1 (IDO1) mediates potent immunosuppression in multiple preclinical models of cancer. However, the basis for elevated IDO1 expression in human cancer, including the most common primary malignant brain tumor in adults, glioblastoma (GBM), is poorly understood. The major objective of this study is to address this gap in our understanding of how IDO1 expression contributes to the biology of GBM, and whether its level of expression is a determinant of GBM patient outcome.

Experimental Design: As most MET inhibitors in clinical development bind the active site with a type I binding mode, we investigated mechanisms of acquired resistance to each MET inhibitor class utilizing in vitro and in vivo models and in glesatinib clinical trials.

Results: Glesatinib inhibited MET signaling, demonstrated marked regression of METex14 del-driven patient-derived xenografts, and demonstrated a durable RECIST partial response in a METex14 del mutation-positive patient enrolled on a glesatinib clinical trial. Prolonged treatment of nonclinical models with selected MET inhibitors resulted in differences in resistance kinetics and mutations within the MET activation loop (i.e., D1228N, Y1230C/H) that conferred resistance to type I MET inhibitors, but remained sensitive to glesatinib. In vivo models exhibiting METex14 del/A-loop double mutations and resistance to type I inhibitors exhibited a marked response to glesatinib. Finally, a METex14 del mutation-positive NSCLC patient who responded to crizotinib but later relapsed, demonstrated a mixed response to glesatinib including reduction in size of a MET Y1230H mutation-positive liver metastasis and concurrent loss of detection of this mutation in plasma DNA.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-1192hwp:master-id:clincanres;1078-0432.CCR-17-1192American Association for Cancer Research2017-11-01Biology of Human Tumors232166616672http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6673?rss=1
Purpose: Bladder cancer is one of the most common urinary malignancies worldwide characterized by a high rate of recurrence and no targeted therapy method. Bladder cancer stem cells (BCSCs) play a crucial role in tumor initiation, metastasis, and drug resistance. However, the regulatory signaling and self-renewal mechanisms of BCSCs remain largely unknown. Here, we identified a novel signal, the KMT1A-GATA3-STAT3 circuit, which promoted the self-renewal and tumorigenicity of human BCSCs.

Experimental Design: In a discovery step, human BCSCs and bladder cancer non-stem cells (BCNSCs) isolated from primary bladder cancer samples #1 and #2, and the bladder cancer cell line EJ were analyzed by transcriptome microarray. In a validation step, 10 paired bladder cancer and normal tissues, different tumor cell lines, the public microarray datasets of human bladder cancer, and The Cancer Genome Atlas database were applied for the verification of gene expression.

Results: KMT1A was highly expressed and responsible for the increase of tri-methylating lysine 9 of histone H3 (H3K9me3) modification in BCSCs compared with either BCNSCs or normal bladder tissue. GATA3 bound to the -1710~-1530 region of STAT3 promoter and repressed its transcription. H3K9me3 modification on the -1351~-1172bp region of the GATA3 promoter mediated by KMT1A repressed the transcription of GATA3 and upregulated the expression of STAT3. In addition, the activated STAT3 triggered self-renewal of BCSCs. Furthermore, depletion of KMT1A or STAT3 abrogated the formation of BCSC tumorspheres and xenograft tumors.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-0882hwp:master-id:clincanres;1078-0432.CCR-17-0882American Association for Cancer Research2017-11-01Biology of Human Tumors232166736685http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6686?rss=1
Purpose: Sarcomatoid renal cell carcinoma (SRCC) ranks among the most aggressive clinicopathologic phenotypes of RCC. However, the paucity of high-quality, genome-wide molecular examinations of SRCC has hindered our understanding of this entity.

Experimental Design: We interrogated the mutational, copy number, and transcriptional characteristics of SRCC and compared these data with those of nonsarcomatoid RCC (RCC). We evaluated whole-exome sequencing, single-nucleotide polymorphism, and RNA sequencing data from patients with SRCC (n = 65) and RCC (n = 598) across different parent RCC subtypes, including clear-cell RCC, papillary RCC, and chromophobe RCC subtypes.

Results: SRCC was molecularly discrete from RCC and clustered according to its parent RCC subtype, though with upregulation of TGFβ signaling across all subtypes. The epithelioid (E-) and spindled (S-) histologic components of SRCC did not show differences in mutational load among cancer-related genes despite a higher mutational burden in S-. Notably, sarcomatoid clear-cell RCC (SccRCC) showed significantly fewer deletions at 3p21-25, a lower rate of two-hit loss for VHL and PBRM1, and more mutations in PTEN, TP53, and RELN compared with ccRCC. A two-hit loss involving VHL predicted for ccRCC and a better prognosis, whereas mutations in PTEN, TP53, or RELN predicted for SccRCC and worse prognosis.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-1057hwp:master-id:clincanres;1078-0432.CCR-17-1057American Association for Cancer Research2017-11-01Biology of Human Tumors232166866696http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6697?rss=1
Purpose: Dasatinib is a short-acting dual ABL/SRC family tyrosine kinase inhibitor (TKI), which is frequently used to treat chronic myeloid leukemia. Although very effective, patients taking dasatinib often display severe adverse effects, including pleural effusions and increased risk of bleeding primarily in the gastrointestinal tract. The actual causes of these side effects are currently undetermined. We hypothesize that endothelial cells (ECs) that line the inner walls of blood vessels and control the traffic to the underlying tissues might be involved.

Experimental Design: The effects of TKIs on ECs were studied by various assays, such as real-time cell impedance measurements, live-cell microscopy, wound healing, Western blot, and an in vivo model.

Results: Dasatinib uniquely causes a profound, dose-dependent disorganization of the EC monolayers. Dasatinib promoted the disassembly of cell–cell contacts, altered cell–matrix contacts, and further altered the wound healing. A key observation is that this effect is fully reversible after drug washout. In line with these in vitro observations, intraperitoneal administration of dasatinib to mice caused significant vascular leakage in the intestine. The underlying molecular mechanism of dasatinib-induced reorganization of the actin involves ROCK activation, which increases the amount of the phosphorylation of myosin light chain and consequently activates the non-muscle myosin II.

Experimental Design: cfDNA from 24 prospectively accrued patients with germline BRCA1 or BRCA2 mutations, including 19 patients with platinum-resistant/refractory ovarian cancer and five patients with platinum and/or PARP inhibitor pretreated metastatic breast cancer, was subjected to massively parallel sequencing targeting all exons of 141 genes and all exons and introns of BRCA1 and BRCA2. Functional studies were performed to assess the impact of the putative BRCA1/2 reversion mutations on BRCA1/2 function.

Results: Diverse and often polyclonal putative BRCA1 or BRCA2 reversion mutations were identified in cfDNA from four patients with ovarian cancer (21%) and from two patients with breast cancer (40%). BRCA2 reversion mutations were detected in cfDNA prior to PARP inhibitor treatment in a patient with breast cancer who did not respond to treatment and were enriched in plasma samples after PARP inhibitor therapy. Foci formation and immunoprecipitation assays suggest that a subset of the putative reversion mutations restored BRCA1/2 function.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-0544hwp:master-id:clincanres;1078-0432.CCR-17-0544American Association for Cancer Research2017-11-01Biology of Human Tumors232167086720http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6721?rss=1
Purpose: Duodenal polyposis and cancer are important causes of morbidity and mortality in familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP). This study aimed to comprehensively characterize somatic genetic changes in FAP and MAP duodenal adenomas to better understand duodenal tumorigenesis in these disorders.

Experimental Design: Sixty-nine adenomas were biopsied during endoscopy in 16 FAP and 10 MAP patients with duodenal polyposis. Ten FAP and 10 MAP adenomas and matched blood DNA samples were exome sequenced, 42 further adenomas underwent targeted sequencing, and 47 were studied by array comparative genomic hybridization. Findings in FAP and MAP duodenal adenomas were compared with each other and to the reported mutational landscape in FAP and MAP colorectal adenomas.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-1269hwp:master-id:clincanres;1078-0432.CCR-17-1269American Association for Cancer Research2017-11-01Biology of Human Tumors232167216732http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6733?rss=1
Purpose: Patients who inherit a pathogenic loss-of-function genetic variant involving one of the four succinate dehydrogenase (SDH) subunit genes have up to an 86% chance of developing one or more cancers by the age of 50. If tumors are identified and removed early in these high-risk patients, they have a higher potential for cure. Unfortunately, many alterations identified in these genes are variants of unknown significance (VUS), confounding the identification of high-risk patients. If we could identify misclassified SDH VUS as benign or pathogenic SDH mutations, we could better select patients for cancer screening procedures and remove tumors at earlier stages.

Experimental Design: In this study, we combine data from clinical observations, a functional yeast model, and a computational model to determine the pathogenicity of 22 SDHA VUS. We gathered SDHA VUS from two primary sources: The OHSU Knight Diagnostics Laboratory and the literature. We used a yeast model to identify the functional effect of a VUS on mitochondrial function with a variety of biochemical assays. The computational model was used to visualize variants' effect on protein structure.

Results: We were able to draw conclusions on functional effects of variants using our three-prong approach to understanding VUS. We determined that 16 (73%) of the alterations are actually pathogenic, causing loss of SDH function, and six (27%) have no effect upon SDH function.

]]>2017-10-31T21:05:55-07:00info:doi/10.1158/1078-0432.CCR-17-1397hwp:master-id:clincanres;1078-0432.CCR-17-1397American Association for Cancer Research2017-11-01Biology of Human Tumors232167336743http://clincancerres.aacrjournals.org/cgi/content/short/23/21/6744?rss=1
Purpose: To elucidate the role and molecular mechanism of Numb in prostate cancer and the functional contribution of Numb–/low prostate cancer cells in castration resistance.

Experimental Design: The expression of Numb was assessed using multiple Oncomine datasets and prostate cancer tissues from both humans and mice. The biological effects of the overexpression and knockdown of Numb in human prostate cancer cell lines were investigated in vitro and in vivo. In addition, we developed a reliable approach to distinguish between prostate cancer cell populations with a high or low endogenous expression of Numb protein using a Numb promoter–based lentiviral reporter system. The difference between Numb–/low and Numbhigh prostate cancer cells in the response to androgen-deprivation therapy (ADT) was then tested. The likely downstream factors of Numb were analyzed using luciferase reporter assays, immunoblotting, and quantitative real-time PCR.

Results: We show here that Numb was downregulated and negatively correlated with prostate cancer advancement. Functionally, Numb played an inhibitory role in xenograft prostate tumor growth and castration-resistant prostate cancer development by suppressing Notch and Hedgehog signaling. Using a Numb promoter–based lentiviral reporter system, we were able to distinguish Numb–/low prostate cancer cells from Numbhigh cells. Numb–/low prostate cancer cells were smaller and quiescent, preferentially expressed Notch and Hedgehog downstream and stem-cell–associated genes, and associated with a greater resistance to ADT. The inhibition of the Notch and Hedgehog signaling pathways significantly increased apoptosis in Numb–/low cells in response to ADT.

Experimental designs:CSF1R germline genetic variants were studied in 140 cancer patients. CSF-1R phosphorylation, endocytosis, and macrophage polarization were measured as the response to CSF-1 stimulation. Tumor-associated macrophages in surgical specimens and sensitivity to CSF-1R inhibitors were used to determine macrophage function.

Results: A CSF1R c.1085A>G genetic variant causing the change of histidine to arginine in the domain of receptor dimerization was identified as a high allele frequency in Eastern Asian population. Cancer patients with this variant allele had less M2-like tumor-associated macrophages accompanied by low VEGF expression in tumor tissues. Importantly, CSF1R genetic variant was significantly associated with disease-free survival in colorectal, endometrial, and ovarian cancer. In terms of differentiation, macrophages with CSF1R c.1085A>G genetic variant displayed a refractory response to CSF-1 stimulation and macrophage survival was sensitive to CSF-1R inhibitors with IC50 of 0.1 to 1 nmol/L range. On contrast, CSF-1 induced a prominent phosphorylation and rapid endocytosis of CSF-1R, leading to an M2-like dominant polarization in macrophages with CSF1R c.1085 genotype A_A, in which CSF-1R inhibitors of PLX3397, BLZ945, and GW2580 inhibited macrophage survival with IC50 of 10 to 100 nmol/L range.

Experimental Design: The influence of low-dose decitabine on T cells was detected both in vitro and in vivo. Moreover, a test cohort and a validation cohort of advanced solid tumor patients with low-dose decitabine-based treatment were involved. The activation, proliferation, polarization, and cytolysis capacity of CD3+ T cells were analyzed by FACS and CCK8 assay. Kaplan–Meier and Cox proportional hazard regression analysis were performed to investigate the prognostic value of enhanced T-cell activity following decitabine epigenetic therapy.

Results: Low-dose decitabine therapy enhanced the activation and proliferation of human IFN+ T cells, promoted Th1 polarization and activity of cytotoxic T cells both in vivo and in vitro, which in turn inhibited cancer progression and augmented the clinical effects of patients. In clinical trials, increased IFN+ T cells and increased T-cell cytotoxicity predicted improved therapeutic responses and survival in the test cohort and validation cohort.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-1201hwp:master-id:clincanres;1078-0432.CCR-17-1201American Association for Cancer Research2017-10-15Cancer Therapy: Clinical232060316043http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6044?rss=1
Purpose: Adenoid cystic carcinoma (ACC) is a rare cancer arising from the major or minor salivary gland tissues of the head and neck. There are currently no approved systemic agents or known radiosensitizers for ACC. Unlike the more common head and neck squamous cell carcinomas that frequently harbor TP53 mutations, ACCs contain TP53 mutations at a rate of <5%, rendering them an attractive target for MDM2 inhibition.

Experimental Design: We report the successful establishment and detailed characterization of a TP53-WT ACC patient-derived xenograft (PDX), which retained the histologic features of the original patient tumor. We evaluated this model for response to the MDM2 inhibitor AMG 232 as monotherapy and in combination with radiotherapy.

Results: Gene set enrichment analysis (GSEA) of PRE, EDT, and PROG melanomas revealed that transcriptome signatures indicative of immune cell activation were strongly positively correlated with PD-L1 staining. In contrast, MAPK signaling and canonical Wnt/-β-catenin activity was negatively associated with PD-L1 melanoma expression. The expression of PD-L1 and immune activation signatures did not simply reflect the degree or type of immune cell infiltration, and was not sufficient for tumor response to MAPK inhibition.

Experimental Design: Trebananib was administered by weekly infusion. Three dose levels (10, 15, or 30 mg/kg/dose) were evaluated using a rolling-six design. Part 2 evaluated a cohort of subjects with primary central nervous system (CNS) tumors. Pharmacokinetic sampling and analysis of peripheral blood biomarkers was performed during the first 4 weeks. Response was evaluated after 8 weeks. Correlative studies included angiogenic protein expression and DCE-MRI.

Results: Thirty-seven subjects were enrolled (31 evaluable for toxicity) with median age 12 years (range, 2 to 21). Two of 19 evaluable non-CNS subjects developed DLT at the 30 mg/kg dose level, including venous thrombosis and pleural effusion. In the CNS cohort, 3/12 subjects developed DLT, including decreased platelet count, transient ischemic attack, and cerebral edema with headache and hydrocephalus. Other grade 3 or 4 toxicities included lymphopenia (n = 4), anemia, thrombocytopenia, neutropenia, vomiting, and hypertension (n = 1 each). Response included stable disease in 7 subjects, no partial or complete responses. Two subjects continued study treatment with prolonged stable disease for 18 cycles (neuroblastoma) and 26 cycles (anaplastic astrocytoma). Pharmacokinetics appeared linear over 3 dose levels. Correlative studies demonstrated increased PlGF and sVCAM-1, but no change in endoglin or perfusion by DCE-MRI.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-16-2882hwp:master-id:clincanres;1078-0432.CCR-16-2882American Association for Cancer Research2017-10-15Cancer Therapy: Clinical232060626069http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6070?rss=1
Purpose: Precise detection of copy number aberrations (CNA) from tumor biopsies is critically important to the treatment of metastatic prostate cancer. The use of targeted panel next-generation sequencing (NGS) is inexpensive, high throughput, and easily feasible, allowing single-nucleotide variant calls, but CNA estimation from this remains challenging.

Experimental Design: We evaluated CNVkit for CNA identification from amplicon-based targeted NGS in a cohort of 110 fresh castration-resistant prostate cancer biopsies and used capture-based whole-exome sequencing (WES), array comparative genomic hybridization (aCGH), and FISH to explore the viability of this approach.

Experimental Design: We used a CTC molecular characterization approach to investigate heterogeneity of 14 hotspot mutations in ESR1 and their correlation with endocrine resistance. Combining the CellSearch and DEPArray technologies allowed recovery of 71 single CTCs and 12 WBC from 3 ER-positive MBC patients. Forty CTCs and 12 WBC were subjected to whole genome amplification by MALBAC and Sanger sequencing.

Results: Among 3 selected patients, 2 had an ESR1 mutation (Y537). One showed two different ESR1 variants in a single CTC and another showed loss of heterozygosity. All mutations were detected in matched cell-free DNA (cfDNA). Furthermore, one had 2 serial blood samples analyzed and showed changes in both cfDNA and CTCs with emergence of mutations in ESR1 (Y537S and T570I), which has not been reported previously.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-1173hwp:master-id:clincanres;1078-0432.CCR-17-1173American Association for Cancer Research2017-10-15Personalized Medicine and Imaging232060866093http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6094?rss=1
Purpose: Molecular profiling in cancer has identified potential actionable drug targets that have prompted attempts to discover clinically validated biomarkers to guide therapeutic decision-making and enrollment to clinical trials. We evaluated whether comprehensive genetic analysis of patients with pancreatic adenocarcinoma is feasible within a clinically relevant timeframe and whether such analyses provide predictive and/or prognostic information along with identification of potential targets for therapy.

Experimental Design: Archival or prospectively acquired FFPE samples and matched normal DNA from N = 336 patients with pancreatic cancer were analyzed using a hybridization capture–based, next-generation sequencing assay designed to perform targeted deep sequencing of all exons and selected introns of 410 key cancer-associated genes. Demographic and treatment data were prospectively collected with the goal of correlating treatment outcomes and drug response with molecular profiles.

Results: The median time from protocol consent to reporting of the genomic results was 45 days with a median time from tissue delivery of 20 days. All genetic alterations identified were stratified based upon prior evidence that the mutation is a predictive biomarker of drug response using the MSKCC OncoKB classification. Three of 225 patients (1%) received a matched therapy based upon the sequencing results.

Experimental Design: Following treatment failure, patients with signed consent and ages above 6 months, underwent tumor biopsy or surgical resection of primary or metastatic tumor site. These newly acquired samples were analyzed by comparative genomic hybridization array, next-generation sequencing for 75 target genes, whole-exome and RNA sequencing. Biological significance of the alterations and suggestion of most relevant targeted therapies available were discussed in a multidisciplinary tumor board.

Results: From December 2012 to January 2016, 75 patients were included, 73 patients underwent 79 interventions, 56 of which were research biopsies with a low complication rate. All patients were pretreated, 37.0% had a brain tumor, and 63.0% had an extra-cranial solid tumor. Median tumor cell content was 70% (range, 0%–100%). Successful molecular analysis in 69 patients detected in 60.9% of patients an actionable alteration in various oncogenic pathways (42.4% with copy-number change, 33.3% with mutation, 2.1% with fusion), and change in diagnosis in three patients. Fourteen patients received 17 targeted therapies; two had received a matched treatment before inclusion.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0381hwp:master-id:clincanres;1078-0432.CCR-17-0381American Association for Cancer Research2017-10-15Personalized Medicine and Imaging232061016112http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6113?rss=1
Purpose: The prevalence of mutations in cancer susceptibility genes such as BRCA1 and BRCA2 and other cancer susceptibility genes and their clinical relevance are largely unknown among a large series of unselected breast cancer patients in the Chinese population.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-16-3227hwp:master-id:clincanres;1078-0432.CCR-16-3227American Association for Cancer Research2017-10-15Personalized Medicine and Imaging232061136119http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6120?rss=1
Purpose: Ethnic differences are conspicuous in melanoma. This study is to obtain a comprehensive view of a genomic landscape and a better understanding of the correlations of gene mutation status with clinicopathologic characteristics and disease prognosis in the Asian population.

Experimental Design: A total of 2,793 melanoma patient samples were retrospectively collected and analyzed for mutations in C-KIT, BRAF, NRAS, and PDGFRA coding regions and telomerase reverse transcriptase (TERT) promoter region by Sanger sequencing. Mutations were correlated to clinicopathologic features and overall survival.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0980hwp:master-id:clincanres;1078-0432.CCR-17-0980American Association for Cancer Research2017-10-15Personalized Medicine and Imaging232061206127http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6128?rss=1
Purpose: We evaluated biodistribution and tumor targeting of 89Zr-lumretuzumab before and during treatment with lumretuzumab, a human epidermal growth factor receptor 3 (HER3)–targeting monoclonal antibody.

Experimental Design: Twenty patients with histologically confirmed HER3-expressing tumors received 89Zr-lumretuzumab and underwent positron emission tomography (PET). In part A, 89Zr-lumretuzumab was given with additional, escalating doses of unlabeled lumretuzumab, and scans were performed 2, 4, and 7 days after injection to determine optimal imaging conditions. In part B, patients were scanned following tracer injection before (baseline) and after a pharmacodynamic (PD)-active lumretuzumab dose for saturation analysis. HER3 expression was determined immunohistochemically in skin biopsies. Tracer uptake was calculated as standardized uptake value (SUV).

Results: Optimal PET conditions were found to be 4 and 7 days after administration of 89Zr-lumretuzumab with 100-mg unlabeled lumretuzumab. At baseline using 100-mg unlabeled lumretuzumab, the tumor SUVmax was 3.4 (±1.9) at 4 days after injection. SUVmean values for normal blood, liver, lung, and brain tissues were 4.9, 6.4, 0.9 and 0.2, respectively. Saturation analysis (n = 7) showed that 4 days after lumretuzumab administration, tumor uptake decreased by 11.9% (±8.2), 10.0% (±16.5), and 24.6% (±20.9) at PD-active doses of 400, 800, and 1,600 mg, respectively, when compared with baseline. Membranous HER3 was completely downregulated in paired skin biopsies already at and above 400-mg lumretuzumab.

Results: CD8+BTLA– TILs could not control tumor growth in vivo as well as their BTLA+ counterpart and antigen-specific CD8+BTLA– T cells had impaired recall response to a vaccine. However, CD8+BTLA+ TILs displayed improved survival following the killing of a tumor target and heightened "serial killing" capacity. Using mutants of BTLA signaling motifs, we uncovered a costimulatory function mediated by Grb2 through enhancing the secretion of IL-2 and the activation of Src after TCR stimulation.

Results: The concurrent addition of anti-PD-1 significantly attenuated the therapeutic effect of anti-OX40 alone. Combination-treated mice had considerable increases in type I and type II serum cytokines and significantly augmented expression of inhibitory receptors or exhaustion markers CTLA-4 and TIM-3 on T cells. Combination treatment increased intratumoral CD4+ T-cell proliferation at day 13, but at day 19, both CD4+ and CD8+ T-cell proliferation was significantly reduced compared with untreated mice. In two tumor models, sequential combination of anti-OX40 followed by anti-PD-1 (but not the reverse order) resulted in significant increases in therapeutic efficacy. Against MMTV-PyMT tumors, sequential combination was dependent on both CD4+ and CD8+ T cells and completely regressed tumors in approximately 30% of treated animals.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-1185hwp:master-id:clincanres;1078-0432.CCR-17-1185American Association for Cancer Research2017-10-15Cancer Therapy: Preclinical232061786189http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6190?rss=1
Purpose: Talimogene laherparepvec, a new oncolytic immunotherapy, has been recently approved for the treatment of melanoma. Using a murine version of the virus, we characterized local and systemic antitumor immune responses driving efficacy in murine syngeneic models.

Experimental Design: The activity of talimogene laherparepvec was characterized against melanoma cell lines using an in vitro viability assay. Efficacy of OncoVEXmGM-CSF (talimogene laherparepvec with the mouse granulocyte-macrophage colony-stimulating factor transgene) alone or in combination with checkpoint blockade was characterized in A20 and CT-26 contralateral murine tumor models. CD8+ depletion, adoptive T-cell transfers, and Enzyme-Linked ImmunoSpot assays were used to study the mechanism of action (MOA) of systemic immune responses.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0681hwp:master-id:clincanres;1078-0432.CCR-17-0681American Association for Cancer Research2017-10-15Cancer Therapy: Preclinical232061906202http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6203?rss=1
Purpose: NRAS mutations in malignant melanoma are associated with aggressive disease requiring rapid antitumor intervention, but there is no approved targeted therapy for this subset of patients. In clinical trials, the MEK inhibitor (MEKi) binimetinib displayed modest antitumor activity, making combinations a requisite. In a previous study, the BRAF inhibitor (BRAFi) vemurafenib was shown to induce endoplasmic reticulum (ER) stress that together with inhibition of the RAF–MEK–ERK (MAPK) pathway amplified its proapoptotic activity in BRAF-mutant melanoma. The present study investigated whether this effect might extent to NRAS-mutant melanoma, in which MAPK activation would be expected.

Experimental Design and Results: BRAFi increased pERK, but also significantly increased growth inhibition and apoptosis induced by the MEKi in monolayer, spheroids, organotypic, and patient-derived tissue slice cultures of NRAS-mutant melanoma. BRAFi such as encorafenib induced an ER stress response via the PERK pathway, as detected by phosphorylation of eIF2α and upregulation of the ER stress–related factors ATF4, CHOP, and NUPR1 and the proapoptotic protein PUMA. MEKi such as binimetinib induced the expression of the proapoptotic protein BIM and activation of the mitochondrial pathway of apoptosis, the latter of which was enhanced by combination with encorafenib. The increased apoptotic rates caused by the combination treatment were significantly reduced through siRNA knockdown of ATF4 and BIM, confirming its critical roles in this process.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0098hwp:master-id:clincanres;1078-0432.CCR-17-0098American Association for Cancer Research2017-10-15Cancer Therapy: Preclinical232062036214http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6215?rss=1
Purpose: HSP90, a highly conserved molecular chaperone that regulates the function of several oncogenic client proteins, is altered in glioblastoma. However, HSP90 inhibitors currently in clinical trials are short-acting, have unacceptable toxicities, or are unable to cross the blood–brain barrier (BBB). We examined the efficacy of onalespib, a potent, long-acting novel HSP90 inhibitor as a single agent and in combination with temozolomide (TMZ) against gliomas in vitro and in vivo.

Experimental Design: The effect of onalespib on HSP90, its client proteins, and on the biology of glioma cell lines and patient-derived glioma-initiating cells (GSC) was determined. Brain and plasma pharmacokinetics of onalespib and its ability to inhibit HSP90 in vivo were assessed in non–tumor-bearing mice. Its efficacy as a single agent or in combination with TMZ was assessed in vitro and in vivo using zebrafish and patient-derived GSC xenograft mouse glioma models.

Results: Onalespib-mediated HSP90 inhibition depleted several survival-promoting client proteins such as EGFR, EGFRvIII, and AKT, disrupted their downstream signaling, and decreased the proliferation, migration, angiogenesis, and survival of glioma cell lines and GSCs. Onalespib effectively crossed the BBB to inhibit HSP90 in vivo and extended survival as a single agent in zebrafish xenografts and in combination with TMZ in both zebrafish and GSC mouse xenografts.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-16-3151hwp:master-id:clincanres;1078-0432.CCR-16-3151American Association for Cancer Research2017-10-15Cancer Therapy: Preclinical232062156226http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6227?rss=1
Purpose: Myxoid liposarcoma is an aggressive disease with particular propensity to develop hematogenic metastases. Over 90% of myxoid liposarcoma are characterized by a reciprocal t(12;16)(q13;p11) translocation. The resulting chimeric FUS–DDIT3 fusion protein plays a crucial role in myxoid liposarcoma pathogenesis; however, its specific impact on oncogenic signaling pathways remains to be substantiated. We here investigate the functional role of FUS–DDIT3 in IGF-IR/PI3K/Akt signaling driving myxoid liposarcoma pathogenesis.

Experimental Design: Immunohistochemical evaluation of key effectors of the IGF-IR/PI3K/Akt signaling axis was performed in a comprehensive cohort of myxoid liposarcoma specimens. FUS–DDIT3 dependency and biological function of the IGF-IR/PI3K/Akt signaling cascade were analyzed using a HT1080 fibrosarcoma-based myxoid liposarcoma tumor model and multiple tumor–derived myxoid liposarcoma cell lines. An established myxoid liposarcoma avian chorioallantoic membrane model was used for in vivo confirmation of the preclinical in vitro results.

Results: A comprehensive subset of myxoid liposarcoma specimens showed elevated expression and phosphorylation levels of various IGF-IR/PI3K/Akt signaling effectors. In HT1080 fibrosarcoma cells, overexpression of FUS-DDIT3 induced aberrant IGF-IR/PI3K/Akt pathway activity, which was dependent on transcriptional induction of the IGF2 gene. Conversely, RNAi-mediated FUS–DDIT3 knockdown in myxoid liposarcoma cells led to an inactivation of IGF-IR/PI3K/Akt signaling associated with diminished IGF2 mRNA expression. Treatment of myxoid liposarcoma cell lines with several IGF-IR inhibitors resulted in significant growth inhibition in vitro and in vivo.

Experimental Design: AZD1775 sensitivity in SCLC cell lines was correlated with baseline expression level of 200 total or phosphorylated proteins measured by reverse-phase protein array (RPPA) to identify predictive markers of primary resistance. We further established AZD1775 acquired resistance models to identify mechanism of acquired resistance. Combination regimens were tested to overcome primary and acquired resistance to AZD1775 in in vitro and in vivo SCLC models.

Results: High-throughput proteomic profiling demonstrate that SCLC models with primary resistance to AZD1775 express high levels of AXL and phosphorylated S6 and that WEE1/AXL or WEE1/mTOR inhibitor combinations overcome resistance in vitro and in vivo. Furthermore, AXL, independently and via mTOR, activates the ERK pathway, leading to recruitment and activation of another G2-checkpoint protein, CHK1. AZD1775 acquired resistance models demonstrated upregulation of AXL, pS6, and MET, and resistance was overcome with the addition of AXL (TP0903), dual-AXL/MET (cabozantinib), or mTOR (RAD001) inhibitors.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-1284hwp:master-id:clincanres;1078-0432.CCR-17-1284American Association for Cancer Research2017-10-15Cancer Therapy: Preclinical232062396253http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6254?rss=1
Purpose: Receptor tyrosine kinases (RTKs) are frequently deregulated in leukemia, yet the biological consequences of this deregulation remain elusive. The mechanisms underlying aberrant methylation, a hallmark of leukemia, are not fully understood. Here we investigated the role of RTKs in methylation abnormalities and characterized the hypomethylating activities of RTK inhibitors.

Experimental Design: Whether and how RTKs regulate expression of DNA methyltransferases (DNMTs), tumor suppressor genes (TSGs) as well as global and gene-specific DNA methylation were examined. The pharmacologic activities and mechanisms of actions of RTK inhibitors in vitro, ex vivo, in mice, and in nilotinib-treated leukemia patients were determined.

Results: Upregulation of RTKs paralleled DNMT overexpression in leukemia cell lines and patient blasts. Knockdown of RTKs disrupted, whereas enforced expression increased DNMT expression and DNA methylation. Treatment with the RTK inhibitor, nilotinib, resulted in a reduction of Sp1-dependent DNMT1 expression, the diminution of global DNA methylation, and the upregulation of the p15INK4B gene through promoter hypomethylation in AML cell lines and patient blasts. This led to disruption of AML cell clonogenicity and promotion of cellular apoptosis without obvious changes in cell cycle. Importantly, nilotinib administration in mice and human patients with AML impaired expression of DNMTs followed by DNA hypomethylation, TSG re-expression, and leukemia regression.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0235hwp:master-id:clincanres;1078-0432.CCR-17-0235American Association for Cancer Research2017-10-15Cancer Therapy: Preclinical232062546266http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6267?rss=1
Purpose: Recent epidemiological and clinical studies have suggested the benefit of aspirin for patients with cancer, which inspired increasing efforts to demonstrate the anticancer ability of aspirin and reveal the molecular mechanisms behind. Nevertheless, the anticancer activity and related mechanisms of aspirin remain largely unknown. This study aimed to confirm this observation, and more importantly, to investigate the potential target contributed to the anticancer of aspirin.

Experimental Design: A homogeneous time-resolved fluorescence (HTRF) assay was used to examine the impact of aspirin on heparanase. Streptavidin pull-down, surface plasmon resonance (SPR) assay, and molecular docking were performed to identify heparanase as an aspirin-binding protein. Transwell, rat aortic rings, and chicken chorioallantoic membrane model were used to evaluate the antimetastasis and anti-angiogenesis effects of aspirin, and these phenotypes were tested in a B16F10 metastatic model, MDA-MB-231 metastatic model, and MDA-MB-435 xenograft model.

Results: This study identified heparanase, an oncogenic extracellular matrix enzyme involved in cancer metastasis and angiogenesis, as a potential target of aspirin. We had discovered that aspirin directly binds to Glu225 region of heparanase and inhibits the enzymatic activity. Aspirin impeded tumor metastasis, angiogenesis, and growth in heparanase-dependent manner.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0242hwp:master-id:clincanres;1078-0432.CCR-17-0242American Association for Cancer Research2017-10-15Cancer Therapy: Preclinical232062676278http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6279?rss=1
Purpose: Glioma tissues consist of not only glioma cells but also glioma-associated nontumor cells, such as stromal cells and immune cells. These nontumor cells dilute the purity of glioma cells and play important roles in glioma biology. Currently, the implications of variation in glioma purity are not sufficiently clarified.

Experimental Design: Here, tumor purity was inferred for 2,249 gliomas and 29 normal brain tissues from 5 cohorts. Based on the transcriptomic profiling method, we classified CGGA and TCGA-RNAseq cohorts as the RNAseq set for discovery. Cases from TCGA-microarray, REMBRANDT, and GSE16011 cohorts were grouped as a microarray set for validation. Tissues from the CGGA cohort were reviewed for histopathologic validation.

Results: We found that glioma purity was highly associated with major clinical and molecular features. Low purity cases were more likely to be diagnosed as malignant entities and independently correlated with reduced survival time. Integrating glioma purity into prognostic nomogram significantly improved the predictive validity. Moreover, most recognized prognostic indicators were no longer significantly effective under different purity conditions. These results highlighted the clinical importance of glioma purity. Further analyses found distinct genomic patterns associated with glioma purity. Low purity cases were distinguished by enhanced immune phenotypes. Macrophages, microglia, and neutrophils were mutually associated and enriched in low purity gliomas, whereas only macrophages and neutrophils served as robust indicators for poor prognosis.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-16-2598hwp:master-id:clincanres;1078-0432.CCR-16-2598American Association for Cancer Research2017-10-15Biology of Human Tumors232062796291http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6292?rss=1
Purpose: Glioblastoma (GBM) is the most common and malignant form of primary human brain tumor in adults, with an average survival at diagnosis of 18 months. Metabolism is a new attractive therapeutic target in cancer; however, little is known about metabolic heterogeneity and plasticity within GBM tumors. We therefore aimed to investigate metabolic phenotyping of primary cultures in the context of molecular tumor heterogeneity to provide a proof of concept for personalized metabolic targeting of GBM.

Results: We found that metabolic phenotyping clearly identifies 2 clusters, GLNHigh and GLNLow, mainly based on metabolic plasticity and glutamine (GLN) utilization. Inhibition of glutamine metabolism slows the in vitro and in vivo growth of GLNHigh GBM cultures despite metabolic adaptation to nutrient availability, in particular by increasing pyruvate shuttling into mitochondria. Furthermore, phenotypic and molecular analyses show that highly proliferative GLNHigh cultures are CD133neg and display a mesenchymal signature in contrast to CD133pos GLNLow GBM cells.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-16-3102hwp:master-id:clincanres;1078-0432.CCR-16-3102American Association for Cancer Research2017-10-15Biology of Human Tumors232062926304http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6305?rss=1
Purpose: Neuroblastoma (NB) is a heterogeneous disease characterized by distinct clinical features and by the presence of typical copy-number alterations (CNAs). Given the strong association of these CNA profiles with prognosis, analysis of the CNA profile at diagnosis is mandatory. Therefore, we tested whether the analysis of circulating cell-free DNA (cfDNA) present in plasma samples of patients with NB could offer a valuable alternative to primary tumor DNA for CNA profiling.

Results: Comparison of CNA profiles on cfDNA showed highly concordant patterns, particularly in high-stage patients. Numerical chromosome imbalances as well as large and focal structural aberrations including MYCN and LIN28B amplification and ATRX deletion could be readily detected with sWGS using a low input of cfDNA.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0675hwp:master-id:clincanres;1078-0432.CCR-17-0675American Association for Cancer Research2017-10-15Biology of Human Tumors232063056314http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6315?rss=1
Purpose: Mutations in Krebs cycle genes are frequently found in patients with pheochromocytomas/paragangliomas. Disruption of SDH, FH or MDH2 enzymatic activities lead to accumulation of specific metabolites, which give rise to epigenetic changes in the genome that cause a characteristic hypermethylated phenotype. Tumors showing this phenotype, but no alterations in the known predisposing genes, could harbor mutations in other Krebs cycle genes.

Experimental Design: We used downregulation and methylation of RBP1, as a marker of a hypermethylation phenotype, to select eleven pheochromocytomas and paragangliomas for targeted exome sequencing of a panel of Krebs cycle-related genes. Methylation profiling, metabolite assessment and additional analyses were also performed in selected cases.

Results: One of the 11 tumors was found to carry a known cancer-predisposing somatic mutation in IDH1. A variant in GOT2, c.357A>T, found in a patient with multiple tumors, was associated with higher tumor mRNA and protein expression levels, increased GOT2 enzymatic activity in lymphoblastic cells, and altered metabolite ratios both in tumors and in GOT2 knockdown HeLa cells transfected with the variant. Array methylation-based analysis uncovered a somatic epigenetic mutation in SDHC in a patient with multiple pheochromocytomas and a gastrointestinal stromal tumor. Finally, a truncating germline IDH3B mutation was found in a patient with a single paraganglioma showing an altered α-ketoglutarate/isocitrate ratio.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-16-2250hwp:master-id:clincanres;1078-0432.CCR-16-2250American Association for Cancer Research2017-10-15Biology of Human Tumors232063156324http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6325?rss=1
Purpose:TP53 is a tumor-suppressor gene that functions as a regulator influencing cellular responses to DNA damage, and TP53 alterations are associated with pejorative outcome in most B-lymphoid disorders. Little is known regarding TP53 alteration in Waldenstrom's macroglobulinemia (WM).

Experimental Design: Here, we have explored the incidence of TP53 alteration using Sanger sequencing and ultradeep-targeted sequencing in 125 WM and 10 immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (MGUS), along with the clinical features and the associated genomic landscape using single-nucleotide polymorphism array and mutational landscape in an integrative study.

Results: Overall, we have identified alteration of TP53 locus including mutation, deletion, and copy-neutral LOH in 11.2% of WM. TP53 mutation was acquired in 7.3% of patients with WM at diagnosis, being absent in IgM MGUS, and was highly correlated to deletion 17p. No correlation with CXCR4 mutations was observed. Patients with TP53 alteration had a greater number of genomic abnormalities. Importantly, WM with TP53 alteration had a significantly shorter overall survival, particularly in symptomatic WM, and independently of the international prognostic scoring system for Waldenstrom macroglobulinemia (IPSSWM) score. Specific treatment for WM with TP53 may have to be studied. Nutlin-3a–targeted p53 signaling induced cytotoxicity preclinically, along with new compounds such as ibrutinib, PrimaMet, or CP31398 that bypass p53 pathway in WM, paving the path for future treatment-tailored options.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0007hwp:master-id:clincanres;1078-0432.CCR-17-0007American Association for Cancer Research2017-10-15Biology of Human Tumors232063256335http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6336?rss=1
Purpose: This study was performed to identify the detailed mechanisms by which miR-296-3p functions as a tumor suppressor to prevent lung adenocarcinoma (LADC) cell growth, metastasis, and chemoresistance.

Experimental Design: The miR-296-3p expression was examined by real-time PCR and in situ hybridization. MTT, EdU incorporation, Transwell assays, and MTT cytotoxicity were respectively performed for cell proliferation, metastasis, and chemoresistance; Western blotting was performed to analyze the pathways by miR-296-3p and HDGF/DDX5 complex. The miRNA microarray and luciferase reporter assays were respectively used for the HDGF-mediated miRNAs and target genes of miR-296-3p. The ChIP, EMSA assays, and coimmunoprecipitation combined with mass spectrometry and GST pull-down were respectively designed to analyze the DNA–protein complex and HDGF/DDX5/β-catenin complex.

Results: We observed that miR-296-3p not only controls cell proliferation and metastasis, but also sensitizes LADC cells to cisplatin (DDP) in vitro and in vivo. Mechanistic studies demonstrated that miR-296-3p directly targets PRKCA to suppress FAK–Ras-c–Myc signaling, thus stimulating its own expression in a feedback loop that blocks cell cycle and epithelial–mesenchymal transition (EMT) signal. Furthermore, we observed that suppression of HDGF–β-catenin–c-Myc signaling activates miR-296-3p, ultimately inhibiting the PRKCA–FAK–Ras pathway. Finally, we found that DDX5 directly interacts with HDGF and induces β-catenin–c-Myc, which suppresses miR-296-3p and further activates PRKCA–FAK–Ras, cell cycle, and EMT signaling. In clinical samples, reduced miR-296-3p is an unfavorable factor that inversely correlates with HDGF/DDX5, but not PRKCA.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-16-2813hwp:master-id:clincanres;1078-0432.CCR-16-2813American Association for Cancer Research2017-10-15Biology of Human Tumors232063366350http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6351?rss=1
Purpose: A major mechanism of castration-resistant prostate cancer (CRPC) involves intratumoral biosynthesis of dihydrotestosterone (DHT) from adrenal precursors. We have previously shown that adrenal-derived androstenedione (AD) is the preferred substrate over testosterone (T) for 5α-reductase expressed in metastatic CRPC, bypassing T as an obligate precursor to DHT. However, the metabolic pathway of adrenal-derived DHT biosynthesis has not been rigorously investigated in the setting of primary disease in the prostate.

Experimental Design: Seventeen patients with clinically localized prostate cancer were consented for fresh tissues after radical prostatectomy. Prostate tissues were cultured ex vivo in media spiked with an equimolar mixture of AD and T, and stable isotopic tracing was employed to simultaneously follow the enzymatic conversion of both precursor steroids into nascent metabolites, detected by liquid chromatography-tandem mass spectrometry. CRPC cell line models and xenograft tissues were similarly assayed for comparative analysis. A tritium-labeled steroid radiotracing approach was used to validate our findings.

Results: Prostatectomy tissues readily 5α-reduced both T and AD. Furthermore, 5α-reduction of AD was the major directionality of metabolic flux to DHT. However, AD and T were comparably metabolized by 5α-reductase in primary prostate tissues, contrasting the preference exhibited by CRPC in which AD was favored over T. 5α-reductase inhibitors effectively blocked the conversion of AD to DHT.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-1313hwp:master-id:clincanres;1078-0432.CCR-17-1313American Association for Cancer Research2017-10-15Biology of Human Tumors232063516362http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6363?rss=1
Purpose: Pancreatic adenocarcinomas (PAAD) often are not diagnosed until their late stages, leaving no effective treatments. Currently, immunotherapy provides a promising treatment option against this malignancy. However, a set of immunotherapy agents benefit patients with many types of cancer, but not PAAD. Sharing the origin in the same organ, diabetes and PAAD tend to occur concurrently. We aimed to identify the impact of diabetes on immunotherapy of PAAD by conducting a comparative genomics analysis.

Results: Differential gene expression analysis revealed a strong enrichment of immunogenic signature genes in diabetic individuals, including PD-1 and CTLA4, that were currently targetable for immunotherapy. Pathway analysis further implied that diabetic individuals were defective in immune modulation genes. Somatic copy-number aberration (SCNA) analysis showed a higher frequency of amplification and deletion occurred in the cohort without diabetes. Integrative analysis revealed strong association between differential gene expression, and epigenetic regulations, however, seemed not affected by SCNAs. Importantly, our somatic mutation analysis showed that the occurrence of diabetes in PAAD was associated with a large set of gene mutations encoding genes participating in immune modulation.

]]>2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-0250hwp:master-id:clincanres;1078-0432.CCR-17-0250American Association for Cancer Research2017-10-15Biology of Human Tumors232063636373http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6374?rss=1
2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-1480hwp:resource-id:clincanres;23/20/6374American Association for Cancer Research2017-10-15Letters to the Editor232063746375http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6376?rss=1
2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-1990hwp:resource-id:clincanres;23/20/6376American Association for Cancer Research2017-10-15Letters to the Editor232063766376http://clincancerres.aacrjournals.org/cgi/content/short/23/20/6377?rss=1
2017-10-12T21:05:52-07:00info:doi/10.1158/1078-0432.CCR-17-1873hwp:resource-id:clincanres;23/20/6377American Association for Cancer Research2017-10-15Letters to the Editor232063776377